An investigation into theft has been handed over to transport police following the incident at the city's Gare du Nord railway station late on February 26, the office said in a statement.

“Although he was careful to point out that his bag contained a professional USB memory stick ... it is important to specify that this stick only contained notes relating to traffic in Paris during the Olympic Games and not on sensitive security plans,” the office said.

Paris 2024 organizers declined to comment.

The Paris Olympics will be held from July 26–August 11.

Some 30,000 members of the police force are expected to be mobilized every day during the Olympics, with about 300,000 spectators expected to attend the opening ceremony along the River Seine.