Senators are going to have to prove where they actually live after media reports alleged three of them reside in the capital fulltime but are claiming living expenses under Senate rules for those who travel to Ottawa for work.

Reports by the Ottawa Citizen and CTV allege Senators Patrick Brazeau, Mike Duffy and Mac Harb are collecting expenses to cover some of their living costs in Ottawa and claiming homes outside the capital as their primary residences, leading a Senate committee to ask administration staff to audit all senators.

Senators who live more than 100 kilometres outside Ottawa can have a second residence in the National Capital Region and receive up to $21,000 a year to cover that expense.

Neighbours and members of the community in Maniwaki, Que., where Brazeau claims a primary residence, told CTV that he was never there. Brazeau sits as a senator from Quebec and reportedly lives in Gatineau, Que.

Duffy, who was appointed to the Senate by Prime Minister Stephen Harper, was a journalist in Ottawa before being appointed to the Senate. According to his official biography, he spent decades working on Parliament Hill. He represents Prince Edward Island in the Senate.

The Canadian Constitution requires senators to live in the provinces from which they are appointed.

Harb was an Ottawa city councillor from 1985 to 1988, when he won a federal seat in the Ottawa Centre riding — the riding in which Parliament Hill sits. Harb was appointed to the Senate directly from the House of Commons in 2003 by then Prime Minister Jean Chrétien. He represents Ontario and reportedly lists a home in Pembroke, Ont., as his primary residence. Pembroke is about 150 km from Ottawa.

Looking for 'sufficient documentation'

A statement from the Senate says its committee on internal economy has instructed the Upper Chamber's administration to do an audit to assess "whether all senators' declarations of primary and secondary residence are supported by sufficient documentation."

The committee had already struck a bipartisan subcommittee to review the allegations about Brazeau. It has now added Harb to that review. Duffy wasn't mentioned in the news release.

A spokeswoman for the Senate said she couldn't say how residency would be assessed. She also wouldn't say anything about the audit before it is finished.

Brazeau told CBC News last week that he was glad the Senate struck a subcommittee to look into the issue.

"I look forward to providing the facts that prove my primary residence is in Maniwaki, Que., contrary to what has been reported," he said in an email.

"I built my reputation on the need for greater accountability and I will continue practising what I preach."

A spokeswoman in Harb's office said he was pleased the committee would be shedding light on the policy.

Allegations have 'really bothered us'

David Tkachuk, the senator who chairs the internal economy committee, says the Senate has tried hard over the past few years to make sure money is being spent properly. The Senate introduced audits several years ago, has been audited by Auditor General Michael Ferguson and will subject individual senators to audits as well, Tkachuk said.

"This thing has really bothered us and so we wanted to clear it up as quickly as possible," he said.

"I know the Senate administration has had meetings with the auditor general's office to make sure that we comply with all the recommendations.... We feel very comfortable about that. These other matters are quite different and of course senators are not happy about the allegations and they want to find out if there's anything to them or not, and they want to know now."

Ferguson said in a report last summer that Senate administration should require documentation on more expense claims. While 99.4 per cent of those claims are reviewed, not all claims for senators' travel and living expenses had the correct supporting receipts or explanations.

Senators who say they live outside the capital must provide annual proof they own the residence, the report said, but in two of the seven cases sampled by the auditor general, Senate administration didn't have the correct documents to support the expense claims.

In another case, the audit team found a living-expense claim that had no purpose stated. Some travel or expense claims had limited information to support the purpose of transaction.

Elizabeth Marshall, a former auditor general in Newfoundland and Labrador, will chair the subcommittee. Marshall was appointed to the Senate by Harper in 2010.