Jacobus Marinus van Nierop, 50, arrived in his home country on Sunday, Radio-Canada reported.
Upon his arrival, van Nierop, who also goes as Mark, was arrested under a warrant issued by France, Radio-Canada said.
Dutch officials are now investigating van Nierop's claims that he murdered his wife in the Netherlands in 2006, said Radio-Canada.
Van Nierop made the admission during an Immigration and Refugee Board (IRB) of Canada detention review hearing on Sept. 5 via teleconference from the Southeast Regional Correctional Centre in Shediac, N.B., where he was being detained.
"His statement was … he thought they would want him to return to his country, which is the Netherlands, because he murdered his wife there in 2006," board spokesman Charles Hawkins had said.
It's unclear whether van Nierop was telling the truth, or if it was just a ploy to avoid extradition to France, where he had been wanted since December on charges of violence causing mutilation or permanent disability.
Van Nierop, who had been practising dentistry in Château-Chinon in the Burgundy region since 2008, allegedly pierced some patients' jaws with poorly placed implants, left parts of dental tools lodged in other patients' gums, and pulled out healthy teeth.
None of the allegations have been proven in court.
Van Nierop arrived in Canada on Dec. 18, 2013, and was admitted as a visitor for six months, according to the IRB.
He was arrested at an apartment in the town of Nackawic on Sept. 1 after RCMP contacted the Canada Border Services Agency about an Interpol "red notice" about him.
During his IRB hearing, van Nierop said he would accept a return to the Netherlands and did not object to his continued detention in Canada, pending arrangements.