Equatorial Guinea says it wants South Africa to extradite Mark Thatcher, son of the former British Prime Minister Margaret Thatcher, for his alleged role in a coup plot against the tiny, oil-rich West African nation.

South African police arrested the 51-year-old businessman at his Cape Town home Wednesday, charging him with helping to finance a plot to overthrow President Teodoro Obiang Nguema of Equatorial Guinea.

Thatcher, who is under virtual house arrest until he's due to appear in a Capetown court in November, denies all charges.

Margaret Thatcher is photographed through a car window as he is driven in a police vehicle. (AP PHOTO)

• FROM AUG. 25, 2004: Thatcher's son charged in coup plot

News of a possible extradition came Friday as a Zimbabwe court found Simon Mann, a former British special forces officer, guilty of attempting to buy arms for the same alleged coup plot.

The court acquitted 66 other suspected mercenaries arrested with Mann when their plane landed in the capital, Harare, in March.

Most of them pleaded guilty to lesser charges of immigration law violations.

A lawyer for Obiang's government, Lucie Bourthoumieux, said that Equatorial Guinea had "strong hopes" of achieving the extradition. But Thatcher's lawyer said Friday that the extradition request had little chance of success.

"I would be interested to know what offence they suggest they might be looking at and what information they might have to support that contention," said defence lawyer Alan Bruce-Brand.

Equatorial Guinea has not announced arrest warrants or formal charges, normally among the first steps in a legal extradition. The South African government, which has no extradition treaty with Equatorial Guinea, said it had not yet received an extradition request. Pretoria does not customarily extradite people to countries where they could face the death penalty.

Equatorial Guinea has put 14 suspected foreign mercenaries on trial for the plotting against the country, which is sub-Saharan Africa's third largest oil producer. Prosecutors have demanded the death penalty for one of them, South African Nick du Toit.

Thatcher has history of legal troubles

Thatcher, a former racecar driver whose alleged multimillion-dollar fortune has long been the source of much speculation, has been in trouble before.

He moved to Dallas in April 1984 after a controversy over reports he represented a British construction firm that won a $600 million contract in Oman while his mother was there on a trade-boosting trip in 1981.

While in Texas, he settled a civil racketeering lawsuit for an undisclosed sum. He also faced charges from the Internal Revenue Service over his role with a Dallas-based home security company that went bankrupt.

Thatcher was also scrutinized by Britain's parliament in 1994 over reports that he was involved in arms sales to Saudi Arabia and Iraq while his mother was prime minister. He moved his family to South Africa in 1995 after the business troubles in the United States.

He denied he was planning to flee South Africa just before his arrest.

Mother 'distressed'

Margaret Thatcher was said by her spokesman on Friday to be "distressed" at the news. She broke off an American holiday but reportedly had no plans to travel to her son's side in South Africa, being confident he would be cleared.

The former prime minister famously let her "Iron Lady" image slip in 1982, when she publicly wept upon hearing her son had gone missing in the Sahara while competing in the Paris-Dakar rally.

The now frail 79-year-old Thatcher last year lost her husband, Sir Denis Thatcher, to cancer.