The murder of Sir Jack Drummond is France's crime of the 20th century
In 1952, Boots' top chemist, Sir Jack Drummond, his wife, Lady Ann, and daughter, Elizabeth, were murdered in the south of France.
A 75-year-old French man, who used a walking stick, was convicted of the brutal murders.
It was France's crime of the 20th Century and to this day the conspiracy theories are abundant.
Were the Drummonds killed by the aged farmer, assassinated by a Soviet spy or caught up in industrial espionage?
BBC Inside Out East Midlands
have investigated the murder mystery for a special programme.
Sir Jack Drummond was the nation's top food chemist.
He researched and defined vitamins as we know them today and during the war, he was the man responsible for rationing based on a scientific diet he had developed.
He was knighted for his wartime work and could be considered the Jamie Oliver of his day for encouraging healthy eating.
And then he left the government.
"It was something of a surprise when he left the Ministry of Food after the war to join Boots in Nottingham as Director of Research," said James Fergusson, author of The Vitamin Murders.
In July 1952, 61-year-old Sir Jack set off with his family, from their home in Nottingham, for a holiday on the French Riviera.
He drove and one night they decided to sleep by the side of a busy road in Provence next to the River Durance.
By the morning they were dead.
Sir Jack and his wife, Lady Ann, had been shot. Their daughter Elizabeth had been beaten to death with a rifle butt.
A 75-year-old farmer named Gaston Dominici was arrested and tried for the murders.
Orson Welles' documentary about the case was never aired
He stayed on death row for three years, before the sentence was reduced to life imprisonment. Dominici was released in 1960 on health grounds.
The question remained what could possibly be his motivation for murder?
Gaston Dominici's grandson, Alain, still maintains his innocence.
He believes the theory that Sir Jack had been a member of the Special Operations Executive during the war and was assassinated by a Soviet agent.
"Let's say the authorities already knew it was a state affair and a military affair," said Alain.
Sir Jack's diary, which has since been lost, appeared to show he had been to the same part of France in 1947.
However, James Fergusson believes the vital question is why were the Drummonds camped where they were?
He thinks Sir Jack may have been involved in some sort of industrial espionage at a nearby chlorine factory.
"There must have been some reason for them to stop by such a busy road," said the writer.
"He was an experienced camper and wouldn't have chosen a spot like that. I think he had arranged some sort of rendezvous with someone from the chemical works."
Whatever the theory no one seems to believe Gaston Dominici committed the crime.
However, it was a case which attracted the interest of Hollywood legend Orson Welles.
He was fascinated by the Dominici Affair and went to France a year after the trial.
The Citizen Kane director recorded the only filmed interviews with Dominici's two sons, Clovis and Gustave, both of whom, initially, accused their father of murder.
But by the time of the interviews it was a very different story.
Inside Out East Midlands investigates the murders