Mohamed Merah
Killer Mohamed Merah in a video frame grab broadcasted by France 2 (Reuters)

A man and a woman have been arrested by French authorities in connection with the slaughter of Jewish schoolchildren and French paratroopers by Islamist killer Mohamed Merah last March.

Police arrested a man suspected of being Merah's girlfriend following a raid on a travelling community in Albi, and also apprehended his former girlfriend in Toulouse, according to AFP.

"[The man] is suspected of having helped Merah in the commission of his acts," a police source told AFP.

Since Merah, 24, carried out a motorcycle shooting rampage that left seven people dead in March, French police have been looking for a "third man" who helped the assailant plan the carnage alongside his older brother Abdelkader.

Abdelkader, who was arrested and charged with complicity within hours of the shootings, confirmed to prosecutors the existence of another accomplice, but refused to reveal the name of his "childhood friend," according to Le Monde.

The man was allegedly present when the powerful scooter used in the attacks was stolen.

Abdelghani Merah, another brother of the killer who spoke against the assassinations, maintained that the "third man" was "from the travelling community".

A police source told AFP the man arrested is a "settled Gypsy converted to Islam".  However authorities warned it is not confirmed the arrested is the "third man," they have been looking for.

Merah shot dead three soldiers, a rabbi and three children at a Jewish school between 11 and 19 March last year. He was eventually shot dead by police after a 32-hour standoff at his flat in Toulouse.