A homeless former British special forces soldier is one of six people who have been charged for the kidnapping of a millionaire French hotel magnate.

Jacqueline Veyrac, 76, the owner of a Michelin-starred restaurant and five star hotel on the French Riviera, was kidnapped on Monday (24 October) in Nice while getting out of her SUV and bundled into a waiting van.

She was released two days later, after being spotted by a passer-by, bound and gagged and tied to the door of the van.

Six people have been charged for their role in the kidnapping, including a former paparazzi photographer, and an Italian restaurateur, AFP reported.

Some face life imprisonment if convicted.

Veyrac, the owner of the Michelin starred La Reserve restaurant in Nice and the Grand Hotel in Cannes, was found bound by the wrists and ankles and with duct tape sealing her mouth and eyes, according to prosecutors. She had sustained injuries attempting to break free, but was otherwise unharmed.

A passer-by spotted the number plate of the van was loose on Thursday, concealing another one underneath, before spotting Veyrac inside.

The former restaurateur, identified only as Giuseppe S, is believed to be the instigator of the plot.

A former manager of La Reserve between 2007 and 2009, he is believed to have formed a resentment towards Veyrac when his company went into liquidation.

He allegedly planned to extract a ransom from Veyrac's family to cover the cost of the liquidation. The kidnappers reportedly contacted Veyrac's family hours after she went missing to demand a ransom.

He has denied any involvement.

The British man, a former special forces soldier now homeless in Nice, allegedly provided surveillance for the gang.

Former paparazzi Luc G, also known as Tintin, allegedly fitted a tracking device to Veyrac's vehicle.

The three others are all alleged to have had a direct role in the kidnapping.

A former police officer arrested is accused of failing to inform law enforcement of the plot when he learnt about it, but is not alleged to have been directly involved. He denies the accusation.

Some members of the gang confessed their role while others deny involvement, French prosecutors said on Sunday.

Police said they were investigating possible links with a failed attempt to kidnap Veyrac in 2013.