Senator Raymond Lavigne, seen in 2002, has agreed to pay back almost $24,000. ((Montreal Gazette/Canadian Press))

The Liberal party has expelled Quebec Senator Raymond Lavigne from caucus after a Senate subcommittee found evidence of misuse of resources.

Lavigne has agreed to pay back almost $24,000 after he was investigated for allegedly using a Senate staffer to work on his home near Wakefield, on the shore of the Gatineau River, north of Ottawa.

A Senate investigation began last year after Lavigne's neighbours filed a complaint.

In a CBC Radio documentary at the time, Neil and Carol Faulkner said they got so used to seeing Daniel Côté working on Lavigne's property, they assumed he must be a relative.

"He was moving stones. He was clearing wood. He cleared a lot of the trees on the other side of the fence," Carol said.

But Côté wasn't a relative. He was a Senate employee on the public payroll.

The senator — a member of the Senate environment committee — had already annoyed his neighbours by building a dock in violation of rules designed to protect the riverbank.

For the Faulkners, the last straw was when they found Côté on their side of the fence cutting trees.

"I would rather that it was not our tax dollars at work cutting down my trees," Neil said.

After the Faulkners complained, a Senate committee began an investigation. On Thursday, it announced that its report was "adverse" to Lavigne. It also referred the file to the Mounties.

Last week, Lavigne was asked to pay back $23,500 to the Senate, which his lawyer said he was prepared to do.

Lavigne, however, has not acknowledged any wrongdoing.

Reacting to the Senate report, Liberal Leader Bill Graham said Lavigne "won't be sitting in the Liberal caucus until this matter is resolved."