A court filing by the lead investigator in a breach-of-trust probe revealed last week that the Mounties are looking in greater depth into the tax returns filed by the former high-profile native leader between 2004 and 2008.
Brazeau was claiming aboriginal tax status at the time, and his driver's licence and passport showed his address as his former father-in-law's house on the Kiniw Zibi Mika First Nation reserve in Maniwaki, Que.
Police, however, allege he was actually living in Gatineau, about 90 minutes away, directly across the river from the national capital.
An official with the Privy Council Office, the bureaucratic wing of the prime minister's office, confirmed that a detailed — but routine — background check was conducted on Brazeau at the time of his 2008 appointment, as is the case for all incoming senators.
That screening involves an RCMP criminal record check, an assessment by the Canadian Security Intelligence Service, a review at Industry Canada to confirm no bankruptcy applications, and a Canada Revenue Agency tax compliance determination.
But the court records show the Gatineau address given to the Mounties for their portion of the review differs from the information on Brazeau's Quebec driver's licence, passport and tax returns.
Police have launched a separate investigation into Brazeau's tax records, which indicate he claimed aboriginal tax credits between 2004 and 2008. That investigation is in addition to a breach-of-trust probe pertaining to Senate housing allowance claims, as well as an ongoing court case involving assault charges.
None of the allegations or charges have been proven in court.
Privy Council Office spokesman Raymond Rivet wouldn't say whether officials flagged the address discrepancy, or even if they noticed it. Rivet declined to comment on the Brazeau case, citing it as "personal information."
He did say the tax backgrounder "looks for significant non-compliance" and that the overall screening process, which has been in place since 1994, is instrumental.
"The background checks were instituted to assist the prime minister in ensuring that there are no criminal, security or other concerns that could affect the suitability of candidates for certain public office positions such as the Senate," Rivet said in an email.
A spokeswoman for Brazeau, Debby Simms, declined to comment because of the ongoing investigations.
NDP ethics critic Charlie Angus, however, accused the Conservatives of wilfully turning a blind eye to the contradictions and red flags that were raised prior to Brazeau's appointment to the Senate.
"If the Privy Council was looking at his tax records, you would have thought they would have spotted these discrepancies," he said.
"When the story started to break, you have to ask yourself whether they took another look, and was the prime minister aware his addresses didn't match?"
Either government officials botched the background check, or the contradiction was buried because the Conservatives wanted to be seen with a high-profile native leader on their team, Angus said.
"Either we're looking at a prime minister who chose to ignore the red flags, or the Privy Council wasn't all that competent in doing the review," he said.
"I find it hard to believe the Privy Council is incompetent."
The RCMP is also investigating senators Mike Duffy and Mac Harb — the first a former Conservative, the latter a former Liberal — on breach of trust allegations in connection with their disallowed Senate expense claims.
An independent audit of expense claims filed by Sen. Pamela Wallin, another former Conservative, has been finalized and is expected to be released next week.
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