Bruce Carson, the former adviser to Prime Minister Stephen Harper who is currently embroiled in controversy, attended high-level meetings months after he had stopped working for the government, the Liberals alleged Wednesday.

In question period, Liberal MP Gerard Kennedy said that in April 2009, three months after he had left the prime minister's office, Carson was at a meeting in Washington, D.C., with former environment minister Jim Prentice and his American counterpart, and other officials. 

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. The Liberals released a photo from the meeting to the media.

"There was nothing sinister about it," Bill Rodgers, the former director of communications for Prentice, said. He was also at the meeting. Rodgers is now director of communications for Prentice's replacement, Environment Minister Peter Kent.

Rodgers said 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.

He said it was "outrageous" that the Liberals are trying to link the Washington meeting with the recent controversy surrounding Carson.

The Liberals also allege that months after that meeting, Carson attended another environment-related meeting on behalf of the government as an official delegate.

"Mr. Carson was there as a representative of the Prime Minister," said Kennedy, who suggested that Carson was in a conflict of interest and that he had special access to Harper after he stopped working for him.

House Leader John Baird acknowledged "serious allegations" are currently surrounding Carson and that Harper properly called the RCMP when they came to his attention. The allegations are related to lobbying activities.

"We expect that every single Canadian obey the law," said Baird.

As for the issue about Carson attending meetings after leaving government, Baird said there was nothing abnormal about it.

"It is not unusual at these climate change negotiations to invite a variety of people representing industry, environmental groups, labour groups, or First Nations or Inuit or Métis people," Baird responded to Kennedy.

Carson's recent work with a water purification company has brought him under scrutiny and prompted Harper to call the RCMP.

He faces accusations that he told H20 Pros he could use his connections to arrange deals between the company and First Nations communities.

A report by the Aboriginal People Television Network suggested Carson's fiancée, Michele McPherson, acted as an intermediary between H20 Pros and the First Nations communities, and stood to earn commission from any sales. It also said she has worked as an escort.

The APTN investigation also alleged Carson 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 Harper's office two years ago and told APTN he is not registered as a lobbyist.

It has also been reported that Environment Minister Peter Kent met with Carson and that he met with senior staff from Indian Affairs Minister John Duncan's office in January, 2011. Duncan's office said the minister did not meet or speak with Carson.

Carson, who was executive director of the University of Calgary's Canada School of Energy and Environment, is taking a leave of absence while the matter is in the hands of the RCMP.