Badges were also taken away from "just under a dozen" people suspected of links to Sri Lankan Tamil Tiger rebels as well as from one Sikh worker.

Another 40 employees at the airport were being investigated as posing a possible security risk, Mr Lebrot said.

Interior Minister Nicolas Sarkozy said the move was necessary as a "precaution".

"It's quite right that the police services conduct inquiries and only certify those people we are certain about," he said.