A terrorist jailed for his part in an attack on the Paris Metro has been given a slap on the wrist by the courts after working as a traffic warden in Richmond - and failing to tell his employers of his criminal past.

Mustapha Boutarfa, now living in north-west London, stood trial in France for his auxiliary role in the 1995 attack on the St Michel metro station, carried out by an Islamic militant group. He was given a two-year jail sentence.

But, in 2005, Boutarfa started working as a traffic warden in Richmond for Vinci Park, then transferred to NCP. Under English law, when a new provider takes over a contract, employees are automatically transferred over, without having their backgrounds checked.

Boutarfa appeared at Richmond Magistrates' Court on October 10, charged with fraud and was handed a 12-month conditional discharge.

A spokesman for NCP services insisted Boutarfa was suspended as soon as they were aware of his previous convictions.

However, had he not accused a van driver of assaulting him in a row over a parking ticket, his criminal past would never have come to light. The case was dismissed as soon as the prosecution revealed Boutarpha's terror conviction.

Tim Cowen of NCP Services said: "Mr Boutarfa was suspended from his job with us as soon as we discovered his previous convictions.

"He was not legally obliged to declare them to us because he was transferred from another company, under Transfer of and Undertaking Protection of Employment legislation, when we took over the contract.

"These rules mean new employers are not allowed to ask transferring staff questions such as whether they have any previous convictions.

"Nonetheless, we acknowledged the public concern about this matter, which was why we immediately suspended him.

"He has subsequently left the company."

A spokeman for Vinci Park said: "We take the precaution of security vetting the relevant positions. However, this process does not cover offences and information held abroad.

"The difficulty is that there is no clear way to check offences committed overseas despite the fact that EU citizens have the right to work in the UK."