Senator Patrick Brazeau is repeating his demand that a Senate committee that ordered him to repay thousands of dollars in living and travel expenses explain its decision at a public hearing.

Last week, the Senate ordered Brazeau to repay $48,000 in expenses because it found he had wrongly declared his primary residence to be in Maniwaki, Que., about 135 kilometres from Ottawa.

Brazeau told Power & Politics host Evan Solomon Thursday the committee's conclusions were contrary to those reached by an audit conducted by the private firm Deloitte.

"[The Deloitte audit] basically concluded that I did not misuse funds. When I did go to Maniwaki, I did claim, when I did not go to Maniwaki, I did not claim," Brazeau told Solomon.

"I was pretty puzzled and surprised at the conclusions of the committee."

Senator Patrick Brazeau says he will fight a Senate committee's order that he repay $48,000 in housing and living expenses. (CBC)

Brazeau said he sent a letter Thursday to Senator David Tkachuk, chair of the Senate's committee on internal economy. Brazeau listed several questions he wants answered, among them:

How did the committee come to its conclusion regarding his primary residence?

Where does Senate policy state the percentage of time one must reside in a location in order for it to be deemed a primary residence?

Why did the committee come to a different conclusion from the outside auditors hired to investigate his expenses?

If the Senate has changed its rules for living and travel expenses, is it ethical for the Senate to enforce the rules retroactively?

"Having an open and transparent airing of these issues would serve the Senate well. Rather than conducting meetings in secret, it would do well to demonstrate its fairness by publicly disclosing its decision-making process," Brazeau said in the letter, which was also addressed to members of the subcommittee that handled the reports, the Senate clerk and the parliamentary counsel.

The letter echoes a press release Brazeau released earlier this week, in which he vowed to fight the Senate's order.

Brazeau continues to insist his primary residence is in Maniwaki and that he shouldn't have to repay money he charged for maintaining another residence near Ottawa, even though an audit by the private firm Deloitte determined he spent only 10 per cent of his time in Maniwaki over an 18-month period.

Brazeau told Solomon his Senate committee commitments keep him in Ottawa five days a week, despite reports that he has a poor Senate attendance record.

Brazeau claims he passed the tests devised by the Senate to determine primary residence. In its audit, Deloitte found his driver's licence, health card and income tax form had addresses that matched his address in Maniwaki, and that he was also able to prove he voted in Maniwaki.

The auditors did report they were "not able to assess the status of the primary residence declared by Senator Brazeau against existing regulations," because the Senate's guidelines for the period did not include criteria for doing so.

But the audit went on to say that Brazeau did meet criteria set by the Senate committee itself, including a provincial health card, driver's license, tax records and voting registration.

"Senator Patrick Brazeau has fully and completely co-operated with Deloitte LLP regarding his residency. All documents have been found to be in order. Deloitte concludes Senator Brazeau meets all 4 Primary Residence Indicators," the audit says.

Despite this, Brazeau's letter points out, the Senate ordered him to reimburse the expenses.

Brazeau also told Solomon he was not approached by the prime minister's chief of staff, Nigel Wright, who wrote a $90,000 cheque to pay the expenses of another senator, Conservative Mike Duffy, nor has he spoken to Wright.

Brazeau was named as a Conservative senator in 2009 by Prime Minister Stephen Harper. He now sits as an Independent after being forced out of the Conservative caucus because he is facing criminal charges for sexual assault.

In a wide-ranging interview with Solomon on Thursday, Brazeau said he could not comment on the criminal charges, which are still before the court, but he said it is possible that he is being "put under the bus" because of the charges and because he is a controversial figure. Brazeau said he is focused on clearing his name.