"As you have observed from the answers to the questions it is patently clear that I had nothing to do with the financing of any coup in Equatorial Guinea," Thatcher told reporters after the hearing, which lasted about an hour. Thatcher last month agreed to plead guilty to violating South Africa's anti-mercenary laws in return for a suspended four-year sentence and a fine of 3 million rand ($500,000).
The case is linked to a group of 70, most since jailed in Zimbabwe, which arrested them last March and charged them with arms and immigration offences relating to the Equatorial Guinea plot. One of those jailed was the group's ringleader Briton Simon Mann, a friend of Thatcher's.
South African prosecutors said they agreed to the plea deal with Thatcher because they were unsure of winning a conviction.
Thatcher had earlier agreed to answer questions from Equatorial Guinean prosecutors, who have alleged that he was part of an international conspiracy to topple the government of the oil-rich West African state. In Friday's hearing Thatcher conceded he knew many of the other people named by Equatorial Guinean officials - including Lebanese oil tycoon Eli Calil and London-based politician-turned-novelist Jeffrey Archer.
"Merely because I have met some of the people of whom questions were asked does not mean to say I had any business relations with them," Thatcher said in court.
He gave terse "yes" and "no" answers to the largely procedural questioning.