An outside auditing firm will probe "residency declarations and related expenses" of three senators, including Patrick Brazeau who was released from a Quebec jail Friday.
Sen. David Tkachuk, chair of the Standing Senate Committee on Internal Economy, announced Friday that Deloitte will review and report the finances of former Tory Brazeau, Liberal Mac Harb and Tory Sen. Mike Duffy.
The senate committee is also seeking legal advice "on the question of Senator Duffy’s residency."
Earlier this week, a Postmedia report suggested Duffy spends the majority of the year at his Ottawa house but claimed more than $33,000 in living allowances since 2010.
In a statement, Duffy said he represents "taxpayers with care."
"I have a home in Prince Edward Island as required by law. I will have no further comment until this review is complete," he said.
All three senators are under review for claiming living allowance costs for a "second residence" in the Ottawa region, when it appears they may not reside elsewhere.
Brazeau was kicked out of the Conservative caucus on Thursday following his arrest at his Gatineau, Que. residence.
Brazeau, who is charged with assault and sexual assault, was released on bail Friday.
The government caucus in the Senate said it intends to bring forward a motion on Tuesday to place Brazeau on a leave of absence.
In November, it was reported Brazeau collected a housing allowance available to senators who reside outside the capital region by claiming expenses for a home in Maniwaki, Que.
Maniwaki is less than a two hour drive from Ottawa.