JOHANNESBURG – Equatorial Guinea could transfer jailed British mercenary Simon Mann to Britain if London arrests other suspects involved in a 2004 coup plot to topple President Theodoro Obiang Nguema.

In an interview on Sunday Nguema told a British weekly that if Britain arrested Sir Mark Thatcher and Ely Calil, Mann could be sent back to a British jail.

He also said that Mann's sentence could be reduced if he continues to "collaborate" with Equatorial Guinea authorities.

"I'll tell you what it will take for him to be allowed to leave my country," said Nguema. "If the British police arrest the people we say were also involved – Ely Calil, Mark Thatcher and others – and bring them to court then maybe we will transfer Simon to an English jail so he can be close to his family.”

Mann, 56 years old and an ex-British SAS officer, was arrested four years ago with 64 others in Zimbabwe when their plane landed in Harare to pick up arms en route to Equatorial Guinea.

The old Etonian served four years in prison in Zimbabwe for trying to purchase weapons without a licence before being extradited to Equatorial Guinea earlier this year where he was jailed for 34 years and fined the equivalent of £119 000 in July for leading an abortive coup to oust the oil-rich West African nation’s president in 2004.

During the trial of Mann, who last March admitted his involvement in the attempted coup saying he had been the "manager, not the architect" of the plot to overthrow Nguema, also named Mark, son of former UK Prime Minister Margaret Thatcher, as among organisers of the plot.

Thatcher was fined in 2005 and received a suspended sentence in South Africa for unknowingly helping to finance the coup plot.

Mann apologised during his trial and admitted his guilt but Carlos Mangue, head of the three-judge panel, said that he had failed to show sufficient regret.

Mangue also ordered José Olo Obano, the country’s Attorney-General, to bring to justice Thatcher and London tycoon Ely Calil, the alleged frontman for a shadowy group of powerful figures who were still determined to seize control of Equatorial Guinea.

Mann alleged in his testimony that Calil – a British businessman of Lebanese descent – was the plot’s mastermind and chief financier, something that Calil has always denied, saying that the plot detailed by Mann in his trial in Malabo was "pure fantasy" concocted by theauthorities for political purposes.

Mann told the court that Thatcher was part of the “management team” and not the “unwitting” financier, as the former Prime Minister’s son has claimed.

Nguema said that since Mann’s incarceration in Black Beach prison in the country’s capital of Malabo, British police had visited Equatorial Guinea three times gathering evidence and Mann had "collaborated brilliantly" with them.

"Simon Mann has collaborated with our government and the British police and if he continues to behave so well, then yes, we will reduce his sentence," the president said.

Police in London confirmed visits to Equatorial Guinea, the paper said.