Canada's Senate has effectively expelled three of its own for what an audit revealed were "troubling" expense claims, as a federal police probe intensified. Conservative senators Mike Duffy, Pamela Wallin and Patrick Brazeau - all of whom were appointed by Prime Minister Stephen Harper - were stripped of their duties, staff and salaries for two years in a Senate vote on Tuesday. But they will keep their health and other benefits. The trio were accused of charging hundreds of thousands of dollars for travel and housing expenses in a scandal that has been a drag on the ruling Conservatives' popularity. Brazeau also faces criminal charges for alleged domestic violence. Duffy, meanwhile, is also being investigated for having accepted a C$90,000 (HK$668,000) cheque from Harper's chief of staff to help the lawmaker repay funds he had wrongly claimed as Senate expenses. Harper's right-hand man, Nigel Wright, resigned in May after revealing the secret payment. Duffy has alleged that the prime minister's office was behind a cover-up to try to quell the uproar, "to make a political situation embarrassing to [Harper's] base go away". As part of the scheme, Duffy said he was told to respond, if asked by reporters where he got the C$90,000 to repay the Senate, that he took out a bank loan, and that it was part of a "script" written for him by the prime minister's office. Harper has steadfastly rejected a barrage of questions about what he knew and attempts to link him directly to the scandal, while pushing for suspending the three senators.