Former French paratroopers wanted for questioning over a string of recent murders, posing in front of Nazi flag. Photo: screenshot via The Sun.

One of three men French authorities are looking to question over their possible involvement in Monday’s killings at a Jewish school in Southern France, has turned himself in.

According to a report from The Daily Mail in the UK, “The man, in his 20s, gave himself up for questioning at a gendarmerie (police station) in Toulouse ‘first thing this morning’.

French officials have confirmed through forensic evidence that one of the guns used in Monday’s rampage was also used last week when members of France’s 17th Parachute Engineer Regiment were shot and killed.

Monday’s killer is also believed to have filmed the attack, according to French Interior Minister Claude Guéant.

The man who turned himself in is believed to have been working at a restaurant in Montauban, France, which was the scene of a shooting last week that is being linked by police to Monday’s attack.

One of the other two men, according to The Daily Mail, “re-joined an Alpine regiment”, while the third “remains unaccounted for”.

Referring to the video camera believed to be around the neck of the killer during Monday’s attack, Guéant said the man must be found.

“The camera is a clue which has been effectively pointed out. It’s an image recorder which you place on the chest, which is adjusted by straps. I don’t know if he films everything but that machine has been seen. It is a national duty that we should arrest this individual.”