Equatorial Guinea prosecutors confirmed Thursday they have charged Mark Thatcher (search), son of former British Prime Minister Margaret Thatcher (search), in an alleged coup plot in the oil-rich west African nation.

Thatcher is accused of having helped finance the coup attempt, Attorney General Jose Olo Obono said.

Thatcher was added to the existing list of 19 other defendants, all accused mercenaries, on Tuesday, Obono said.

Equatorial Guinea intends to seek Thatcher's extradition, a legal official close to the government's case told The Associated Press earlier this week.

Equatorial Guinea alleges Thatcher and other, mainly British financiers, worked with Equatorial Guinea opposition figures, scores of South African mercenaries, and six Armenian pilots in a takeover plot here.

The coup plotters intended to force out the 25-year regime of President Teodoro Obiang (search), installing an exiled opposition figure in his stead as a figurehead leader for Africa's No. 3 oil producer, Equatorial Guinea claims.

The alleged plot was exposed in March by South African intelligence services, and scores of accused mercenaries arrested here and in Zimbabwe.

Thatcher was arrested in August at his home in South Africa.

Trial resumed Thursday, with prosecutors' lead witness formally facing the death penalty after repudiating his alleged confessions in the case in court on Tuesday.