Bruce Carson, a former top adviser to Stephen Harper with a history of fraud convictions, faces accusations that he told Ottawa-based water purification company H20 Pros he could use his connections to arrange deals with First Nations communities.

Carson was the prime minister's chief policy analyst and troubleshooter from 2006 until 2008, when he left the Prime Minister's Office (PMO) to head up the Canada School of Energy and Environment, a co-ordinating agency for clean energy research set up by three Alberta universities and funded by a federal grant. He returned to the PMO briefly in January 2009 before going back to the institute in February of that year.

Two letters from that time released by the Conservative Party in April 2011 indicate that while at the PMO in 2009, Carson may have been lobbying on behalf of the Canada School of Energy and Environment for a $25-million grant that was later awarded to another research institute Carson was affiliated with named Carbon Management Canada. The letters also make it clear that at least some members of Harper's senior staff were worried enough about Carson's possible conflicts of interest to alert the federal conflict of interest and ethics commissioner.

Carson's lawyer has told CBC News that Carson was up-front about his past fraud convictions during a required security screening for the PMO job.

Opposition leaders have slammed Harper on the election campaign trail, questioning how Carson was able to get into the inner circle of the prime minister. Harper says he was aware of Carson's convictions from the 1980s but that if he'd known about the latest allegations of influence peddling, he would not have hired him.

According to Canadian Press reports, Carson also has other political ties. He did freelance work for the Liberal caucus research bureau between 1984 and 1990, during John Turner's leadership. He served in the Progressive Conservative research service at the Ontario legislature and for Conservative senators on Parliament Hill during the 1990s.

Timeline of events

Dec. 12, 2011: CBC News reports that the federal lobbying commissioner has completed a report of her eight-month investigation into Carson's activities and it could be made public shortly. A separate conflict-of-interest investigation by the federal ethics commissioner was quietly suspended in November pending the outcome of an RCMP probe into Carson’s affairs.

Oct. 11, 2011: CBC News reports the taxpayer-funded Canada School of Energy and Environment was left to pay personal expenses charged by Carson during his time as head of the think-tank.

Sept. 23, 2011: The RCMP and the federal commissioners of lobbying and ethics confirm their separate investigations into Carson are continuing.

April 20, 2011: Conservative Party officials release copies of two letters sent in January 2009 by Stephen Harper's former chief of staff Guy Giorno to the federal conflict of interest and ethics commissioner alerting her to a possible conflict of interest involving Bruce Carson and his relations with the Canada School of Energy and Environment. At the time, Carson was on leave from his post as executive director of the research institute and working for the PMO.

Sources tell CBC News the commissioner also received a third letter about Carson from then deputy minister of the environment Ian Shugart.

These letters seem to contradict Harper's earlier claims that prior to the 2010 allegations of influence peddling, senior staff had no prior inkling there was anything amiss about Carson.

April 6, 2011: Questioned on the campaign trail, Stephen Harper says he does not know who conducted the security check on Carson, but adds he is troubled by the latest revelations.

CBC News reports that the current head of the RCMP, William Elliott, was responsible for giving Carson security clearance. At the time, Elliott was serving as national security adviser in the Privy Council Office (PCO), the bureaucracy that supports the prime minister.

April 4, 2011: The Canadian Press reports that Carson was convicted on five counts of fraud — three more than previously known — and received court-ordered psychiatric treatment prior to his hiring as an adviser to Stephen Harper.

Harper says he was aware of Carson's fraud convictions in the 1980s, but didn't know Carson's criminal record was more extensive or that he received court-ordered psychiatric treatment before working for the PMO. He says that if he'd known about the new allegations against Carson, he would not have hired him.

"He was well-regarded. On that basis, the Privy Council Office gave him a security clearance," Harper said. "The fact is, I did not know about these revelations that we're finding out today. I don't know why I did not know."

March 25, 2011: Ottawa businessman Patrick Hill, head of water filter company H20 Global Group, denies Carson lobbied on his behalf. In an interview with CBC News, Hill says, "Carson advised me on a few things, how to deal with INAC [Indian and Northern Affairs Canada] and stuff like that," but he adds that there was no written contract between the two men.

Though he met with Carson, Hill says he was already talking to First Nations officials. "But straight up, Mr. Carson, I never paid him a nickel. I’m actually glad that the RCMP is involved, because he never took a nickel, I never gave him a penny or anything else like that."

March 23, 2011: The Liberals allege in Question Period that Carson attended high-level meetings in Washington, D.C., with former environment minister Jim Prentice and his American counterpart, and other officials in April 2009, three months after he had stopped working for the government. According to the Liberals, Carson was introduced to the meeting as an adviser to Prentice, who left politics last fall for a job in the private sector.

Bill Rodgers, the former director of communications for Prentice, was at the meeting and says Carson was an "unpaid adviser" to the deputy minister of the environment at the time, Ian Shugart, and attended the meeting in that capacity. Carson was considered an expert on energy and climate change issues, said Rodgers, and was hired, but not paid, to give his advice to Shugart. Rodgers could not say how long Carson acted as an adviser to Shugart, who has since left the environment department.

March 18, 2011: The chair of the Canada School of Energy and Environment's board of directors defends the organization's decision to hire the former senior prime ministerial aide despite his brush with the law in 1982. "Absolutely, we've reviewed that," Brian Heidecker told CBC News.

"That's a very serious situation, but 25 years of unblemished service after that, we seem to have the opinion he had learned his lesson."

March 17, 2011:report by the Aboriginal Peoples Television Network suggests Carson's fiancée, Michele McPherson, acted as an intermediary between H20 Pros and the First Nations communities, and stood to earn commissions from any sales. It also said the 22-year-old has worked as an escort.

The APTN investigation alleges Carson had lobbied officials at the Department of Indian and Northern Affairs Canada. It's illegal for former senior staffers to lobby for five years after they leave their jobs. Carson left two years ago and told APTN he is not registered as a lobbyist.

A spokeswoman for Indian Affairs Minister John Duncan says someone from their office met with Carson on . 11, 2011, although it's not declared on the federal lobbyist registry. It's up to the lobbyist to declare meetings with public office holders.

March 16, 2011: The Prime Minister's office says Stephen Harper has referred allegations about Carson to the RCMP. The PMO also informs the conflict of interest office, the ethics commissioner and the lobbying commissioner about the allegations against Carson, Harper spokesman Dimitri Soudas says in an email.

A spokesman for Harper issues a statement that the prime minister has never met with, spoken with or been lobbied by Carson on "these matters," though he didn't specify what those matters are.

Carson, who became executive director of the University of Calgary's Canada School of Energy and Environment, issues a statement that night saying he is taking a leave of absence until the RCMP probe is completed.

Aug. 31, 2010: According to APTN, Michele McPherson signs a contract that would entitle her to 20 per cent of the gross sales in a project Carson was supporting.

Dec. 1, 2009: The Harper government approves a $25-million grant for Carbon Management Canada, a research institute chaired by Carson.

Feb. 4, 2009: Carson officially leaves the PMO and returns to Canada School of Energy and Environment, whose focus he shifts to promoting Alberta oilsands and helping the Harper government navigate climate change issue.

. 23, 2009: Giorno sends two letters to federal Conflict of Interest and Ethics Commissioner Mary Dawson alerting her to the possible conflicts of interest involving Carson.

. 13, 2009: Stephen Harper's chief of staff at the time, Guy Giorno, informs Carson that a "conflict of interest screen" has been set up that prevents him from involvement with any matters related to the Canada School of Energy and Environment, the University of Calgary and Networks of Centres of Excellence, a government agency that funds joint research projects between academia and industry. Sources have told CBC News the commissioner also received a third letter about Carson from then deputy minister of the environment Ian Shugart.

. 6, 2009: An email is sent from Carson's account to Deputy Minister of Natural Resources Cassie Doyle lobbying for a $25 million grant on behalf of the Canada School of Energy and Environment. At the time, Carson was on leave from his post as executive director of the research institute and working for the PMO. Carson later claimed the email had been drafted before he returned to the PMO and was sent in error. The Harper government subsequently approved a $25-million grant for Carbon Management Canada, another research institute chaired by Carson.

. 5, 2009: Carson returns to the PMO after securing an unpaid leave of absence from the Canada School of Energy and Environment.

Sept. 7— Oct. 15, 2009: Carson takes a leave from the PMO to work as an adviser to Harper on the election campaign.

Sept. 2, 4, 2008: Documents filed under the Lobbying Act, and revealed later by Harper's former chief of staff Guy Giorno, indicate Carson was lobbied by the University of Calgary on these dates while he was employed at the PMO and still head of Canada School of Energy and Environment.

Aug. 14, 2008: Carson is named executive director of the Canada School of Energy and Environment, a co-ordinating agency for clean energy research set up by the University of Calgary, the University of Alberta and the University of Lethbridge and funded by a federal grant. He remains an employee of the PMO until Nov. 6, 2008

Feb. 6, 2006: Official start date of Carson's employment with the PMO.

2002: Documents show Carson had $369,000 in "liabilities" and was forced to put forward what is known as a "proposal," which is one step short of bankruptcy and allows the individual to work out a deal to pay his debts.

1993: Documents show Carson declared bankruptcy, with a debt of $103,000.

1990s: Carson serves in the Progressive Conservative research service at the Ontario legislature and for Conservative senators on Parliament Hill, according to reports by The Canadian Press.

1990: While working as a researcher for the Library of Parliament, Carson is charged with defrauding a Budget Car and Truck Rental of a 1989 Toyota vehicle. He is also charged with defrauding the Bank of Montreal and the Toronto-Dominion Bank of sums exceeding $1,000 each. In June, he pleads guilty to all three counts of fraud. He receives a suspended sentence and 24 months probation on condition that he "continue treatment at the R.O.H. (Royal Ottawa Hospital)," and make restitution of $4,000 within 23 months to the car rental company.

1984 to 1990: Carson does freelance work for the Liberal caucus research bureau during John Turner's leadership, The Canadian Press reports.

Early 1980s: Carson is jailed and disbarred by the Law Society of Upper Canada for two counts of defrauding clients. A summary of the disbarment finding against him in 1981 said his "fiscal position had deteriorated due to a land development project in which he had become involved and due to an extravagant lifestyle."

1980: Carson is ordered by a judge to come up with more than $3,000 plus interest after failing to pay money owed on the lease of a Lincoln Continental, according to a report by the Ottawa Citizen.

May 1979: Carson and his then-wife default on mortgage payments, prompting the Supreme Court of Ontario to issue a writ allowing a savings and loan company to take possession of the property, the Ottawa Citizen reports. He is also sued by Hudson Bay Co. for $1,189.50 owing on merchandise, according to the report.

1978: Carson is ordered in a court judgment to pay more that $1,900 to a company after a cheque bounced, says a report by the Ottawa Citizen.

1977: According to reports in the Ottawa Citizen that cite court documents, Carson and his then-wife were sued by a developer that sought to recover an Ottawa home.