Equatorial Guinea seeks to extradite Sir Mark Thatcher

Sir Mark Thatcher, the son of the former prime minister Baroness Thatcher, is facing a new attempt to extradite him to Equatorial Guinea, the oil-rich West African enclave where he was allegedly involved in an attempted coup.

The country's attorney-general said that authorities would continue to "go after" Sir Mark by issuing an international arrest warrant.

He added that as an alleged accomplice in the 2004 plot, Sir Mark would face a 30-year jail term.

The developments come as Simon Mann, the Old Etonian ex-SAS officer who was to have led the so-called "Wonga Coup", awaits trial in Malabo, the capital of Equatorial Guinea. He was brought there from Zimbabwe two months ago.

He has named his alleged co-conspirators. Top of the list are Sir Mark and Ely Calil, a multimillionaire British-Lebanese businessman alleged to have been the chief financier of the plot.

Jose Olo Obono, Equatorial Guinea's attorney-general, said: "We will have to pursue all those people who organised the attempted coup. Equatorial Guinea will have to go after them, we are not going to let this drop."

He named six targets for prosecution including two Britons, Greg Wales and David Tremain, and two more Lebanese.

Mr Obono showed reporters a contract signed in Sir Mark's name with Triple A Aviation for the charter of a helicopter, ostensibly for use as an air ambulance.

He claimed that the contract also covered the hire of a jet that was to have brought Severo Moto, an exiled opposition leader, back to Malabo to head the new government installed by the mercenaries.

The plot, however, fell apart at Manyame military airbase in Zimbabwe, where Mann and around 70 other mercenaries were arrested.

Sir Mark has always denied plotting or knowingly financing a coup, but in a plea bargain with the South African government, where he was living at the time, in January 2005 he admitted violating its Foreign Military Assistance Act by hiring a helicopter which "Mann and others planned to use in mercenary activity in Equatorial Guinea".

He was fined about £260,000 and now lives in Spain.

A family friend said: "This is another damaging attempt to slur Sir Mark's name.

"Equatorial Guinea has no extradition treaty. They can say all sorts of things but whether or not they are actually going to issue an Interpol warrant or doing anything substantial I doubt. They are just stringing this story along."