The court in Malabo, the capital, also fined Mann $235,000 on Monday, and ordered that he be barred from entering Equatorial Guinea's territory for a further 20 years after his sentence is served.

Mohamed Salaami, Mann's co-accused, was jailed for 18 years and three months with the same fine and territorial bar applied.

Mann, a former army officer, was arrested in March 2004 along with 61 other suspected coup plotters when their aircraft landed in Zimbabwe.

Mann also implicated Mark Thatcher, the son of Britain's former prime minister Margaret Thatcher, in the plot.