QUEBEC -- Former Quebec lieutenant-governor Lise Thibault arrived at a detention centre on Thursday to begin serving her 18-month prison term for fraud and breach of trust.

Thibault will be detained at a Quebec City facility.

The province's top court rejected her appeal Wednesday that would have seen her serve the sentence in the community.

Thibault, 76, was sentenced last fall to 18 months in jail for the fraud and breach of trust.

She pleaded guilty in December 2014 after a 2007 report by the federal and provincial auditors general revealed she claimed more than $700,000 in improper expenses when she held the vice-regal post between 1997 and 2007.

Her lawyer, Marc Labelle, has not yet said whether he will take the case to the Supreme Court of Canada.

Thibault's trial heard the money was allegedly spent on gifts, trips, parties, meals and skiing and golf lessons.

Trial judge Carol St-Cyr called her behaviour "highly reprehensible" and part of a "culture of deceit."

Thibault, who was also ordered to pay back $200,000 to the federal government and $100,000 to Quebec, testified she had little to show financially for her time as vice-regal -- a divorce ate into her savings and she said she was living on a $30,000 pension.

St-Cyr ruled against a pair of motions filed by Labelle, who argued the case should have been dismissed because the accused benefited from royal immunity.

Labelle said that meant Thibault was not a civil servant and therefore could not face criminal charges.

The judge said constitutional law stipulates the lieutenant-governor does not enjoy the same benefits as the Queen.

St-Cyr also noted that under the Constitution, the lieutenant-governor is a civil servant, adding such an affirmation was even posted on the lieutenant-governor's website.