According to AFP, a judicial source has confirmed that the man who stole the briefcase containing sensitive information on security plans for Paris 2024 has been arrested and sentenced to seven months in prison for the crime. The defendant appeared in court in the French capital on Friday following the theft, which took place on a train at Gare du Nord on Monday night. 

The briefcase belonged to an engineer working for Paris City Hall, who had placed it in the luggage compartment above his seat and was surprised to find it stolen by the 23-year-old. The crime raised concerns when a police source said the briefcase contained a computer and two USB sticks with security plans for the Paris Olympics.

Days later, however, the Paris prosecutor's office said the USB drive "contained only notes on road traffic in Paris during the Olympic Games and no sensitive security information".

The suspect was "known" to the police for repeated thefts on public transport, particularly in early January, the judicial source said. In addition to being a repeat theft offender, the defendant was also charged with refusing to give his phone code to the authorities.

A statement from Paris City Hall said that the city employee was being investigated to determine whether he had violated any internal security rules by travelling with the USB key, suggesting that this was not a minor incident and that the contents of the briefcase were of concern to the Paris authorities.

Some 35,000 security personnel will be on duty during the Olympic Games, which run from 26 July to 11 August, including some 2,000 municipal police officers from the capital. As well as crowd control and crime prevention, police will be on high alert for possible terrorist attacks, as France has been a target of Islamist extremists over the past decade.