Mark Thatcher won a two-month reprieve on Tuesday from a court order that he answer questions from Equatorial Guinea about his alleged involvement in a coup plot in the oil-rich nation, his lawyer said.

Judge John Hlophe granted a request from state prosecutors that Thatcher's testimony - initially scheduled for Wednesday - be postponed to November 26, said lawyer Alan Bruce-Brand.

Thatcher's lawyers went before the Cape Town High Court to try to quash a subpoena ordering the son of the former British prime minister to answer questions under oath.

"We met on Tuesday to arrange the postponement which was by agreement" with the state prosecution, Bruce-Brand told reporters after a brief meeting in the judge's chambers.

The judge also set October 26 and 27 as the dates for hearing the lawyer's arguments that the subpoena should be overruled because it violates Thatcher's right to remain silent.

The South African justice minister agreed earlier this month to a request from Malabo prosecutors to put questions to Margaret Thatcher's son, who has been charged with helping to finance the alleged coup plot.

Thatcher was arrested on August 25 in Cape Town and charged with bankrolling the alleged plot to overthrow President Teodoro Obiang Nguema, who has ruled Equatorial Guinea for 25 years.

He is due to appear in court on November 25 to answer charges of violating South Africa's anti-mercenary law.

If convicted, Thatcher could face a fine or a jail sentence, or both. - Sapa-AFP