By Lee Carter BBC News, Toronto

Paul Martin has tried to distance himself from the scandal

Testimony considered potentially damaging to Canada's Liberal government has been heard for the first time at an inquiry into a corruption scandal.

The testimony came from an advertising executive whose firm was paid millions of dollars by the government.

Jean Brault said illegal contributions had been made to the Liberal Party.

The executive was heard behind closed doors last week. But a judge lifted the publication ban on his testimony after it became available on a US website.

Justice John Gomery said it was in the public interest to release most of Mr Brault's deposition.

Mr Brault is owner of the Groupaction advertising agency, which is at the centre of the corruption scandal.

It was under the previous Liberal Prime Minister Jean Chretien in the late 1990s that advertising contracts were awarded to Liberal-friendly advertising firms in Quebec to raise the federal government's profile in the province.

It followed a 1995 referendum result in French-speaking Quebec, when the province came close to deciding to separate from the rest of the country.

In early 2004 the annual report from Canada's auditor general found there had been a gross misuse of millions of dollars of government money.

The report said that often little or no work was performed by the agencies and that normal accounting practices had not been followed.

Public anger

In the newly-released testimony, Mr Brault alleges that kickback contributions totalling nearly $1m were made to the Liberal Party by the Quebec advertising companies.

He also alleges Liberal Party workers were put on Groupaction's payroll and that the advertising firm became a virtual wing of the Liberal Party in Quebec.

Mr Brault says he took orders from very senior figures in Mr Chretien's government.

Both the current and former Canadian prime ministers testified before the public inquiry in February.

Mr Chretien defended the programme as a patriotic attempt to defend Canada's interests in Quebec. He said if mistakes were made, those responsible should be brought to justice.

Although the current Prime Minister Paul Martin was finance minister at the time, he told the inquiry he knew very little about its operations.

He is not linked by the testimony so far, and he has personally pledged to get to the bottom of the corruption scandal.

Public anger over the scandal is believed to have been partially responsible for reducing the Liberal Party's majority to a minority in an election last year.

But it remains to be seen whether Canadians have an appetite for being forced to go to the polls again over the issue.