The family of Sir Mark Thatcher, who was arrested in South Africa last week on suspicion of financing a coup attempt in oil-rich Equatorial Guinea, quit his Cape Town home tdoay bound for the United States.
The 51-year-old son of British former Prime Minister Margaret Thatcher is effectively under house arrest in the plush residence until he pays a 2 million rand (€250,000) bond.
Mr Thatcher has denied involvement in the plot.
His acquaintance Mr Simon Mann, a former British special forces officer, was convicted in Zimbabwe on Friday on weapons charges linked to the suspected coup.
Mr Thatcher's Texan wife Diane and two children left their house this evening, speeding past waiting journalists and through rush hour traffic in a luxury four-wheel-drive vehicle with darkened windows, escorted by guards in a second vehicle.
Followed on their high-speed journey by a media convoy, the family drove to Cape Town airport's international terminal, where they were taken to the check-in desks and away from the cameras.
A family spokesman, Lord Tim Bell, said the family was bound for the United States, where the children were to be enrolled for the new school year. He said the move had been planned months ago and had nothing to do with Mr Thatcher's arrest.
Equatorial Guinea is trying 19 men, 14 of them foreigners, suspected of plotting to topple President Teodoro Obiang Nguema Mbasogo, who has led sub-Saharan Africa's third largest oil producer since 1979.
Prosecutors have demanded the death penalty for one of them, South African Nick du Toit.
Mr Thatcher is under orders to remain in South Africa pending a November court appearance. Equatorial Guinea has asked South Africa for permission to interview him on suspicion of being one of the main backers of the coup.
South African police say Thatcher had planned to leave the country before he was arrested, having put his home up for sale and winding up other aspects of his life in the country.
Mr Thatcher, who moved to Cape Town from the United States in 1998 but frequently travelled between the two, was ordered by a South African magistrate to hand in all travel documents and air tickets.