A senator charged with fraud and banned from sitting in the upper chamber since 2007 continues to charge taxpayers more than $10,000 a month in travel, hospitality and office expenses on top of his $133,000 a year salary.

RCMP charged Senator Raymond Lavigne with fraud, breach of trust and obstruction of justice over the alleged misuse of Senate funds for travel, and getting a staffer to do personal work for him.

Lavigne was kicked out of the Liberal caucus, and for almost four years, he has not been allowed to sit on Senate committees or set foot in the Senate chamber without special permission from the Speaker.

Lavigne, who's from Quebec, has repaid $24,000 since being charged.

Senator Raymond Lavigne, charged with fraud, billed taxpayers $30,787 in expenses in one three-month period last fall. (Montreal Gazette/Canadian Press)

But while his case has dragged on, he has been allowed to continue spending public funds.

Government documents reveal that in one three-month period last fall, Lavigne billed taxpayers $30,787 in expenses on top of roughly $33,000 in pay.

Those charges to the public purse include over $8,400 in travel, $17,708 in "office" costs, and $4,528 for living expenses in the Ottawa area.

Since he was barred from the Senate chamber in 2007, Lavigne has cost Canadian taxpayers more than $700,000.

Exactly what kind of Senate work Lavigne does for his paycheque and expense claims has remained something of a mystery.

His website carries a large banner notice that is an apparent attempt to explain what he has been doing during the time he hasn't been sitting in the Senate.

It reads: "According to the rules of the Senate of Canada, Sen. Raymond Lavigne participates in public business throughout the country."

Elsewhere on his website, it says that on one occasion, his public business was meeting with "some of the best-known Quebec artists."

Numerous colour photographs of the senator in a grocery store attest to his work in the community, having been "present at the grand opening of a new IGA store."

An independent audit released last month was harshly critical of the entire Senate for spending taxpayer dollars without necessary controls, often without senators having to produce receipts.