Mark Thatcher, son of British Prime Minister Margaret Thatcher, was reported missing in the Sahara desert while competing in the Paris-Dakar rally on this day in 1982.

Thatcher, 28, his co-driver and mechanic had last been spotted two days previously, driving in convoy with two other cars near the border between Mali and Algeria. It later transpired that they had become separated after stopping to repair a damaged rear axle.

The trio, driving a Peugeot 504, waited for help and told the other members of their convoy to report their position. Unfortunately, these cars’ crews passed on the wrong location to the rally's organisers. With only a compass to help them navigate, Thatcher and his team were hopelessly lost.

Margaret Thatcher leaves the Imperial Hotel in London after breaking down in tears in concern for her missing son.

The Prime Minister’s son, a motor racing enthusiast, had taken part in the Le Mans 24 Hour race in 1980 and 1981. He was then asked by his eventual co-driver, Anne-Charlotte Verney, to take on the gruelling Paris-Dakar Rally, but later admitted making no special preparations for it.

A huge search-and-rescue operation was launched, with spotter planes and helicopters dispatched to find the missing crew, while Thatcher’s father Denis flew out to Algeria to assist with the hunt.

The Prime Minister, naturally upset at her son’s disappearance, faced television reporters looking unusually stressed, telling them: "I'm afraid there is no news".

Mark Thatcher (left) and co-driver Charlotte Verney are rescued after six days in the Sahara.

After six days, with the crew’s supply of food running low and water rationed to two cups each a day, they were finally spotted by an Algerian air force plane. Thatcher and his father were reunited and flown back to the UK in the Algerian presidential jet.

He claimed to have not been distressed by his dilemma, saying: "When [they] didn't come back for us in the first day I remember planning to be out there…for two weeks. That was very important psychologically. I was never scared for my life."

[Also On This Day: January 12, 1976 - Best-selling crime writer Agatha Christie dies]