A British mercenary admitted in an interview broadcast on Tuesday he plotted to oust Equatorial Guinea's President Teodoro Obiang Nguema Mbasogo in 2004 but the "swashbuckling" scheme failed.

Speaking to Channel 4 News in prison in the capital of the oil-producing African country, former British army officer Simon Mann said he should have pulled the plug on the coup plot and was now deeply sorry.

"It was a fuck-up and I have to carry the can for that. Now I blame myself most for simply not saying 'cut' two months before we were arrested. That's what I should have done and there, you know, I was bloody stupid. Mea culpa," he said.

The plot trained an international media spotlight on Mann, - the heir to a brewing fortune who attended Britain's exclusive school Eton - and the scramble for access to Africa's rich offshore oil fields.

Obiang seized power in a 1979 coup in which he killed his uncle and his rule has long been seen as one of the most authoritarian on the continent.

Equatorial Guinea is now Africa's third largest oil producer behind Nigeria and Angola and has faced sharp international criticism for human rights abuses.

Mann, 55, is a former member of elite British special forces who later helped found two security firms that became bywords for mercenary activity across Africa in the 1990s.

He was arrested in March 2004 when he met a plane carrying dozens of men and military equipment which landed in Zimbabwe's capital Harare on what officials said was the first stop on their way to ousting Obiang.

NOT THE "MAIN MAN"

"I was involved. And I was, if you like, the manager. Below me were quite a number of people. Including those who were arrested with me in Zimbabwe, including those who are ... doing prison sentences here," said Mann, hands and feet shackled.

Mann faces charges in Equatorial Guinea of plotting to overthrow Obiang and faces a possible life sentence. He said his confession in the interview was not part of a plea bargain.

"I've been helping the authorities here as best I can with this sorry story," he said.

"And of course, above me in the machine, were other people as well. So I was, if you like, the manager. Not the architect. And not the main man," he said.

In 2004, Equatorial Guinea requested international arrest warrants for those it suspected of involvement. They include London-based businessman Eli Calil and Severo Moto, who leads a self-proclaimed Equatorial Guinean government-in-exile in Spain.

Both have repeatedly denied any link to the plot.

In 2004 South African police arrested Mark Thatcher, the son of former British Prime Minister Margaret Thatcher, on suspicion of bankrolling the scheme. He denied any links and eventually agreed a plea bargain deal with South African authorities.

Mann was jailed for four years by a Zimbabwean court in 2004 for buying weapons without a licence - which the prosecution said were intended for the coup. He was extradited to Equatorial Guinea earlier this year.

"You go tiger shooting and you sort of don't expect the tiger to win."