Canadian Prime Minister Justin Trudeau addresses supporters during a Liberal Party fundraiser in Surrey, British Columbia, on Sunday. Photo: Darryl Dyck/The Canadian Press via AP

Toronto – Canada's ethics commissioner said on Wednesday that Prime Minister Justin Trudeau improperly pressured the country's former attorney-general to halt the criminal prosecution of a company in a conflict of interest case.

The report comes just before the official start of campaigning for the October 21 general election and it threatens to reinflame a scandal that rocked the government earlier this year, causing a drop in poll ratings that had since abated.

Ethics commissioner Mario Dion said Trudeau's attempts to influence the former attorney-general and justice minister, Jody Wilson-Raybould, were contrary to the constitutional principle of prosecutorial independence.

"The prime minister, directly and through his senior officials, used various means to exert influence over Ms Wilson-Raybould," Dion wrote.

"The authority of the prime minister and his office was used to circumvent, undermine and ultimately attempt to discredit the decision of the director of public prosecutions as well as the authority of Ms Wilson-Raybould."

Wilson-Raybould believes she was demoted from her role as attorney-general and justice minister to veterans' affairs minister in January because she didn't give in to pressure to enter into a remediation agreement with a Canadian company accused of bribing officials in Libya.

That potential solution would avoid a potential criminal conviction that would bar Quebec engineering giant SNC-Lavalin from receiving any federal government business for a decade. The company is a major employer with 9 000 employees in Canada and about 50 000 worldwide.

The report said Trudeau "directed his staff to find a solution that would safeguard SNC-Lavalin's business interest in Canada".

The scandal led to multiple resignations, including that of Gerry Butts, Trudeau's top aide and best friend. And it damaged the party for weeks.

The damage from it abated this summer, but the ethics report could reignite the controversy at an inopportune time for Trudeau.

A spokesperson for Trudeau said he would issue a statement and take questions later.

AP