The Liberal leader said Friday that Sen. Mac Harb did the right thing by deciding to sit as an Independent while an investigation continues into housing allowances.
"This is why I was comfortable and happy with Mac's decision to step away from the Liberal caucus," he said. "There are questions to be answered. Mr. Harb and Mr. Brazeau are having their say and they are challenging the allegations, so we will allow processes to take their place."
Harb resigned from the Liberal caucus after an independent audit found he'd improperly claimed $51,500 in Senate housing allowances.
Trudeau, who met shoppers and office workers as they went about their business at lunch Friday at a mall in Halifax, refused to say whether he thought Harb should step down from the Senate.
Harb is contesting a demand that he repay the money.
Senate Speaker Noel Kinsella says the RCMP's sensitive and international investigations unit is examining the claims of Harb and senators Mike Duffy and Patrick Brazeau.
Trudeau says the problem goes beyond individual senators and all the way up to Prime Minister Stephen Harper, who he said was ethically irresponsible in avoiding questions about his former chief of staff's payment to Duffy.
Nigel Wright resigned Sunday as Harper's chief of staff after it emerged he had footed the $90,000 bill for Duffy's disallowed housing expenses.
Duffy has also left the Conservative caucus.
He repaid $90,000 in disallowed living expenses with the help of a secret cheque from Wright. After repaying the money, Duffy stopped co-operating with a team of independent auditors.
Duffy spoke out Thursday for the first time since the scandal erupted last week, insisting that he looks forward to a complete airing of all the facts and dismissing suggestions he should resign his Senate seat.
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