One of Bernie Ecclestone's helicopter pilots was behind a plot to kidnap his mother-in-law in Brazil for a £28 million ransom, according to police.

Aparecida Schunck, the mother of the Formula One boss's wife Fabiana Flosi, 38, was abducted from her home in Sao Paulo more than a week ago.

Police said they rescued the 67-year-old after finding her tied up but unharmed in a house on the outskirts of Sao Paulo on Sunday.

Pilot Jorge Eurico da Silva Faria, who works for Ecclestone in Brazil, is one of three men arrested in connection with the kidnapping, said police.

It is believed investigators monitored phone calls between the family of Ms Schunck and the captors, tracing them to the location where she was being held.

She was was not harmed in the operation conducted by Sao Paulo's anti-kidnapping division.

Elisabete Sato of Sao Paulo police told the BBC that the ransom, thought to have been the largest in Brazilian history, had not been paid.

Ecclestone, 85, married Ms Flosi in 2012, three years after meeting her at the Brazilian Grand Prix.

Brazilian magazine Veja had reported that the ransom for Ms Flosi's mother had been demanded in pounds sterling and divided into four bags of cash.

Ecclestone has declined to comment on the abduction. It is understood he wanted to fly to Brazil to assist police and also offered the use of a private security company to deal with the abductors.

Brazil is hosting this year's Olympic Games in Rio de Janeiro, which starts this week.

Security has emerged as the top concern, including violence possibly spilling over from Rio's hundreds of slums.

Authorities have said they will be prepared and that 85,000 police and soldiers will be patrolling during competition.

A spokesman for Sao Paulo police said da Silva Faria was arrested "red handed" with two other men, Vitor Oliveira Amorim and David Vicente Azevedo.

"The investigation continues and the police did not rule out the involvement of other suspects," he added.