MONTREAL -- A Surete du Quebec police officer found guilty of a dangerous driving death of a five-year-old boy has lost his appeal and must turn himself in to serve his sentence.

The Quebec Court of Appeal tossed out the case in a ruling issued Tuesday. The officer, Patrick Ouellet, must serve the eight-month sentence he received in 2018. The trial judge also handed out a 20-month driving suspension as part of the sentence. 

The victim was a passenger in his father's car when it was struck by an unmarked police cruiser driven by Ouellet the morning of Feb. 13, 2014. Ouellet was on duty doing surveillance at the time of the crash and was travelling at an estimated 110 km/h on a 50 km/h residential street in St. Hubert, Que., south of Montreal. 

Ouellet, then 29, had been following a former director general of Quebec's Liberal party at the time of the crash as part of an investigation by the province's anti-corruption unit. 

The Crown initially refused to lay charges, saying that the boy's father had made a risky turn, but there was a public outcry and a new investigation was ordered by Quebec’s justice minister.

The Quebec Association of Provincial Police Officers criticized the ruling, saying Ouellet acted according to the teachings of his police force. 

"A directive does exist at the Surete du Quebec in matters of chasing, urging caution," they wrote in a statement. "However, a directive is one thing and teachings and operational management is another. In our opinion it's more the instruction to never lose a subject, well-established in this environment, which contributed to this horrible accident."

The union criticized "the absence of clear directives compatible with the reality on the ground" and called for the Public Safety Ministry to put in place clear rules for chases "in order to prevent such human repeating in the future."

- With files from The Canadian Press