Former governor general Michaelle Jean has praised the appointment of Julie Payette to the job, saying the ex-astronaut will be "extraordinary" in her new duties.

"Let's be delighted, let's be delighted she has been selected," Jean told The Canadian Press on Monday.

"She has a renown that precedes her. She is one of those pioneers, one of those women who has been able to take excellence to the highest level."

Two incidents involving Payette surfaced two weeks ago: a dismissed charge of second-degree assault when she lived in Maryland in 2011 and a fatal car accident in which she was not found at fault.

Jean, who served as governor general between 2005 and 2010, said Payette needs to be fully respected for her worth and accomplishments.

Payette called the assault charge "unfounded'' and noted she was "immediately cleared.''

An online background check search showed Payette was charged with second-degree assault on Nov. 24, 2011. The prosecutor formally dismissed the charge about two weeks later.

The online records don't detail what led to the charge. The records also don't turn up in official Maryland records searches, suggesting they were expunged from the public record.

Political appointees in Canada are normally run through a thorough vetting process designed to root out personal history that could be damaging for the candidate and government should they become public. Depending on what is found, the government may move on to another candidate.

Prime Minister Justin Trudeau has said Payette went through the same check as other high-profile political appointees.

He has not said whether the check turned up the two incidents or whether he talked with Payette about either case.

And in a statement issued through Rideau Hall a fortnight ago, Payette declined to comment.

"For family and personal reasons, I will not comment on these unfounded charges, of which I was immediately and completely cleared many years ago, and I hope that people will respect my private life,'' it said.