(Adds reaction from Harb's lawyer, paragraphs 7-9)
OTTAWA Feb 4 (Reuters) - Canadian police laid fraud charges against a senator and a former senator on Tuesday following an expenses scandal that has rocked the country's unelected Senate and tainted the Conservative government of Prime Minister Stephen Harper.
The fraud and breach-of-trust charges were laid by the Royal Canadian Mounted Police against Mac Harb, a Liberal appointee who resigned from the Senate in August, and Patrick Brazeau, who was expelled from the Conservative caucus last year and then suspended from the Senate because of what were deemed to be inappropriate expense claims.
The charges have not been proven in court.
"These investigations were detailed and involved the careful consideration and examination of evidence," Gilles Michaud, commanding officer of the Mounties' national division, said in a nationally televised statement.
"Our investigators interviewed dozens of individuals and witnesses. As is typical with any investigation, we also reviewed and analyzed thousands of documents, including financial statements, bank records and expense claims which dated back to 2003," he said.
The controversy stems from housing and living expenses the two men claimed. Harb and Brazeau have both said that they followed Senate rules in claiming expenses and that the rules were changed and unfairly applied retroactively.
Harb's lawyer Sean May said his client looked forward to being in court to be able to answer the charges, which he denies.
"He is prepared to respond and to respond vigorously to the accusations," May said.
The first court appearance is likely in the next few weeks, but the trial is not likely for a year, he added.
Brazeau did not provide an immediate reaction.
Along with Brazeau, two other Conservative appointees involved in controversy over their expense claims have been suspended from the Senate. These two have also said they are innocent of wrongdoing.
Michaud said work was continuing on "other significant files."
Police said in November they were investigating Harper's former chief of staff, Nigel Wright, on suspicion that he acted corruptly in giving his own money to one of the suspended senators, Mike Duffy, to help Duffy pay back expenses the Senate said he should not have claimed.
Wright has said he acted within the scope of his duties and has voiced confidence his actions were lawful.
With the scandal reaching into Harper's office, the Conservatives have been hurt in the polls. The party came to power in 2006 pledging clean and accountable government.
The scandal has also damaged the reputation of the Senate, the upper house of Canada's parliament, whose members are appointed rather than elected, spurring calls from across the political spectrum for the chamber to be reformed or abolished. (Editing by Jeffrey Hodgson; and Peter Galloway)