Some 250 prisoners and 25 employees of a Quebec City prison have been ill since last night with what the director of Public Health is calling food poisoning.

A dishwasher at the prison, in the Charlesbourg borough of Quebec City, may be the cause. The hot steam cycle of the machine, which sterilizes the dishes, had stopped working.

The dishwasher was reportedly installed four weeks ago.

Stéphane Lemaire, the president of the prison guards’ union, said the prison’s management decided to transfer some of those affected to other establishments.

"It seems there’s a group that was sent to Rimouski and the people there find that a little too fast. They’ll probably have to quarantine those people," he said.

Christine Barthes of the Ministry of Agriculture, Fisheries and Food confirmed an investigation is underway.

The results of this investigation will be known in seven to 10 days, she said.

The kitchen has been closed, and prisoners and personnel still at the detention centre were fed a catered lunch today.