Johannesburg - Lawyers representing 70 accused mercenaries held in Zimbabwe appealed to South Africa on Tuesday to intervene to prevent their extradition to Equatorial Guinea where they could face the death penalty.
The group has been held at the Chikurubi high security prison complex in Zimbabwe's capital Harare since being arrested in March on suspicion of plotting a coup in Equatorial Guinea.
They are charged with conspiring to topple the government of Equatorial Guinea President Teodoro Obiang Nguema as well as immigration, firearms and aviation offences.
Defence lawyer Alwyn Griebenow told a news conference in Johannesburg the group wanted South Africa to intervene to ensure they got a fair trial and to prevent a possible extradition to the oil-rich west African nation.
"These are South African citizens... South Africa must ensure they get a fair trial," he said.
"South Africa must also intervene and speak to the Harare government to ensure the men are not extradited to a country where they obviously face capital punishment," he added.
Most of the men are from South Africa, Namibia and Angola and all have South African passports. They were seized after authorities impounded their plane during a stop in Harare.
South Africa's foreign ministry said last week it had no legal basis to prevent an extradition of the men to Equatorial Guinea but had provided consular services to them.
Last week the governments of Zimbabwe and Equatorial Guinea signed an extradition accord that defence lawyers said could be a prelude to transferring the detainees. The Harare government has not publicly commented on such a possibility.
Griebenow said all of the men had been assaulted during interrogation and had also been intimidated. Some were held in solitary confinement while at least one was stripped naked and questioned by as many as eight security agents at a time.
Relatives and friends had been denied access to the men, who have been in leg irons since last week after what Zimbabwean prosecutors said was a plot to spring them from jail.
Francois Joubert, another defence lawyer, rejected the escape claim as "very laughable, a joke".
"It is not possible that anyone would plan to escape from Zimbabwe's top security facility. It is simply not possible to even think about it," he told the same news conference.
Griebenow insisted the men were not mercenaries and were en route to the Democratic Republic of Congo to provide mine security.
Defence lawyers had also been denied physical access to their clients and were forced to take their instructions in the presence of prison warders or security agents, he added.
"I cannot see how you can have a fair trial under such circumstances," he said.
The defence has asked a Harare magistrate to have the charges against the men dismissed on the grounds that they were either defective in law or could not be supported by fact.
On Monday magistrate Mishrod Guvamombe adjourned the case to Thursday, when lawyers said he was likely to hear evidence in private on the alleged escape plot.