OTTAWA—Prime Minister Justin Trudeau says he is "deeply disappointed" by how Toronto MP Yasmin Ratansi handled her office.
Ratansi said Monday she's leaving the Liberal caucus after admitting she employed a relative at her constituency office.
Speaking at a news conference in Ottawa, Trudeau said Ratansi's behaviour is unacceptable and he expects a thorough follow up by the House of Commons administration.
Ratansi, who represents Don Valley East, said in a statement posted to Facebook Monday night that she "made an error" by employing her sister
Ratansi said in the post that she had informed the Prime Minister's Office as well as the Speaker.
She apologized to her constituents and said she intends to continue representing the riding as an Independent.
"We need to know that there are strong rules in place to ensure that (MPs) behave properly," Trudeau said Tuesday. He said he learned of the apparent nepotism on Monday.
"We always expect the very best of all of them, in our party and all parties. We will continue to hold that high standard."
Conservative ethics critic Michael Barrett called on Ratansi to resign.
"Liberal MP Yasmin Ratansi knew it was wrong to employ her sister with taxpayer dollars, yet she went to great lengths to cover up this information," said Barrett in a statement.
"Canadians deserve better from their elected leaders."
The issue has been referred to the ethics commissioner and Ratansi said she is waiting to hear his recommendations.
Ratansi has represented the Ontario riding since 2015, and previously held the riding from 2004 to 2011.