The ransom demand is the largest in Brazilian history and is thought to have been requested in cash. The Brazilian magazine Veja reported that the ransom had been demanded in pounds sterling and divided into four bags. Mr Ecclestone, 85, married Ms Flosi in 2012, three years after meeting her at the Brazilian Grand Prix.
Brazil is hosting this year's Olympic Games in Rio de Janeiro which start next week. Security has emerged as the top concern, including violence possibly spilling over from Rio's many slums. There has been no confirmation from Brazilian officials or from Ecclestone's staff in London.
"We neither confirm nor deny this report," a spokesman for the regional security ministry told AFP.
The Ecclestone story is shocking.
— Sam Roberts (@samrobertsrugby) July 27, 2016
If anyone kidnapped my mother in law and asked for £28m, I'd say I'll give you £14m and you can keep her.
This is the policy in cases of suspected kidnapping, to avoid putting the lives of potential victims in danger. According to Globo, the kidnappers are already in contact with the victim's family.
