The RCMP believes Senator Patrick Brazeau committed breach of trust by filing inappropriate travel and housing expense claims, according to court documents filed today.

Cpl. Greg Horton, the lead investigator looking into the living and travel claims of senators Mike Duffy, Mac Harb and Brazeau, is asking the court to order the Senate to hand over information such as attendance records, Senate cellphone and credit card statements, and expense claim forms.

Similar paperwork has been filed with the court for the RCMP's investigations into Harb and Duffy. They are also alleged to have committed breach of trust. Duffy is also being investigated for accepting a $90,000 cheque from Prime Minister Stephen Harper's former chief of staff, Nigel Wright, to cover the inappropriate expense claims.

Questions arose last year about Brazeau's claim that his primary residence was in Maniwaki, Que., about 135 kilometres from the capital. The home belongs to his father. Brazeau told the Senate that the home he rented in Gatineau, Que., just across the Ottawa River from Parliament Hill, was his secondary residence. He began claiming the living and travel allowances for that residence in 2011.

Senators whose primary residences are more than 100 kilometres away from Ottawa are entitled to reimbursements for travel to the capital and for maintaining a secondary residence for working in Ottawa.

Following an external audit and Senate report in the spring, Brazeau was ordered to repay taxpayers $48,000.

Brazeau, a former Conservative senator who left the caucus following charges of assault and sexual assault that are before the courts, is disputing the order and the Senate is now docking his salary.

Brazeau lived in Gatineau when appointed

"Based on the information and evidence gathered to date, I believe that Senator Brazeau has committed breach of trust by filing inappropriate living and travel claims since April 2011," Horton said in the court document.

He said Brazeau lived in Gatineau when he was appointed to the Senate in 2008 in a house that he owned with his wife at the time. "By all accounts, that was his primary residence. Within three months of his marriage failing in late 2010, Brazeau moved into a rental home in Gatineau, where he lived for the next 27 months," Horton said.

The investigator said that Brazeau's girlfriend at the time and her children moved into the Gatineau home by June of 2011. A number of people were interviewed as part of the investigation including neighbours of the Maniwaki and Gatineau homes. They told the RCMP they believed Brazeau lived permanently in Gatineau.

His former girlfriend told the RCMP that she and Brazeau lived together for 20 months and that he did not live in Maniwaki. She said he would visit there and sometimes when she and Brazeau visited his father they would stay in a hotel so as not to disturb him.

"The investigation has shown that Brazeau does not live in Maniwaki, nor does he own a home there. Brazeau's father resides in Maniwaki, but the senator, since being appointed to the Senate, has not," the court document alleges.

Other questions about where Brazeau lived and the addresses he was using were part of the RCMP's investigation.

Income tax claims to be investigated

The court document said that when Harper was considering appointing Brazeau to the Senate the Privy Council Office requested a security check by the RCMP. The address provided was the home he shared with his wife at the time in Gatineau.

His driver's licence at the time of his appointment, however, said he lived at 9 Kiniw Zibi Mikan. That's Brazeau's former father-in-law's address on a reserve in Maniwaki. The reserve's chief told the RCMP Brazeau never lived in the community and the former father-in-law said the senator never lived with him.

He used the same address when he applied for a passport in March 2007, "when in fact he owned and lived in a house in Gatineau at the time," the court document states. A CTV News story in February reported that Brazeau used his former father-in-law's address on the reserve when filing for aboriginal tax exemptions between 2004 and 2008.

"Further investigation pertaining to those income tax claims and Brazeau's use of his former father-in-law's address will be conducted," Horton wrote.