The Conservative leader in the Senate says she plans to ask the auditor general to look into all expenses of the red chamber.

Sen. Marjory LeBreton said she will introduce a motion on Tuesday that calls for a comprehensive audit, which will put the entire Senate under a microscope.

“When I say a comprehensive audit of all Senate expenses, I mean just that,” LeBreton told CTV’s Power Play on Monday. “Every tax payer dollar that’s spent to the functioning of the Senate all of it…I chose my words carefully.”

LeBreton said it’s “very clear” that the Canadian public is wants more accountability from the upper house as the Senate expense scandal continues to widen.

“The public saw the Senate as a closed club, investigating itself,” she said. “I came to realize that we really had to respect what the public was saying and turn it over to a body that is absolutely, without question, has a lot integrity and a lot credibility and actually assure the public that we are serious about tax payer dollars.”

While Liberal Senate leader James Cowan said he supports calling on the auditor general to probe Senate expenses, he said the investigation should extend to the House of Commons as well.

LeBreton said investigation could put pressure on her colleagues in the House of Commons.

However, she added: “I think they’re ahead of us right now in terms of accounting for their expenses.”  

Meanwhile, the RCMP said it is determining whether it will launch a criminal investigation into the scandal.

“We’ve started to meet with some potential witnesses and we have reviewed some documents,” Assistant Commissioner in charge of the force’s new National Division, Gilles Michaud, told reporters in Ottawa Monday.

“We have received some documents from the Senate that have been very useful in bringing us along in our assessment around conducting a criminal investigation or not.”

Michaud would not give a timeframe for a decision, and said when the force does decide whether to launch a criminal probe, the decision will not be made public.

Senate leaders had previously confirmed that they have turned documents related to the matter over to the RCMP.

Michaud said he had “no concerns” when asked if he felt the force would be free to conduct an investigation into Parliamentarians’ activities without political interference.

“The RCMP has full independence around the carriage of its criminal operations,” he said.

During the House of Commons’ daily question period, the opposition has continued to hammer Prime Minister Stephen Harper over what he knew about a cheque Sen. Mike Duffy used to repay over $90,000 in improperly claimed expenses.

CTV News learned last month that Nigel Wright, Harper’s former chief of staff, had written Duffy a personal cheque to repay the expenses, prompting some to demand an RCMP investigation.

In addition to Duffy, two other senators -- Patrick Brazeau and Mac Harb -- were ordered to pay back housing expenses deemed to be improperly claimed by an outside audit.

Canada’s Ethics Commissioner Mary Dawson has opened a probe into the $90,000 cheque, while the Senate’s ethics committee is investigating the whole expenses affair.

In a letter to NDP ethics critic Charlie Angus, the RCMP confirmed that the National Division’s Sensitive and International Investigations Section is also reviewing the payment to Duffy.

“What the RCMP have confirmed is that they are looking into the issue now of the $90,000 payment from Nigel Wright to Senator Duffy,” Angus told reporters in Ottawa on Monday. “That’s a significant piece of what we’ve asked for because we have concerns whether or not this deal was illegal. If the RCMP is looking into the prime minister’s office we believe that’s a major step.”

The RCMP were responding to a letter Angus sent on May 20, asking for the police to investigate the issue.

Hot topic in question period

On Monday afternoon, Liberal MP Bob Rae repeated his party’s calls for a public inquiry.

“Mary Dawson is carrying out a private inquiry into the matter of Nigel Wright. The Senate ethics officer is carrying out a private inquiry in to the matter of Mike Duffy,” Rae said during question period. “Why not have one public inquiry to deal with the fact that Nigel Wright gave something to Mike Duffy?”

“It was this House that brought in legislation giving the tools to independent watchdogs for them to be able to consider these matters. What we’re simply doing is following Canadian law as passed by this House, as passed by this Parliament to look into these matters,” Foreign Affairs Minister John Baird replied.

“This issue has been referred to at least two independent authorities, and the government will completely co-operate with these authorities.”

Auditors are also examining the travel expenses of Sen. Pamela Wallin, but the results of that probe have not yet been released.

Wright resigned when news of the $90,000 cheque broke, and the Prime Minister has maintained he knew nothing about the arrangement until it was reported in the media.

On Monday, Baird dodged a question from NDP MP Megan Leslie about whether the RCMP had contacted the prime minister’s office since last week, when Harper said his office had not heard from the Mounties about the expenses affair.

Baird repeated the government’s pledge to co-operate with “the independent bodies set up to independently look at these types of situations.”