Mr John Gilligan, who is fighting extradition to Ireland on a charge of murdering journalist Veronica Guerin, has been writing Christmas messages to possible witnesses in the case against him.
Several people whose statements to gardai are contained in the book of evidence against Mr Gilligan have received letters from him in the past month.
The letters were sent from the new high-security prison at Highdown, in Surrey. He was transferred to this prison two weeks ago from Belmarsh Prison after an incident in which a prison officer was assaulted.
The letters from Highdown have arrived at the homes of relatives of the three main State witnesses in the case against him.
Mr Gilligan apparently inquires after the families' health and says he wants them to know he is innocent of the charges against him. He accuses the Garda of "plotting" against him and of holding grudges against him, and says he will be able to prove this to be true in court.
It is understood he also states in one of the letters that he understands the witnesses have been "made" make statements by the gardai. Mr Gilligan was furnished with the book of evidence, as is normal in criminal trial procedure.
According to sources close to the case, Mr Gilligan has kept up a very active life in the high-security prisons he has been held in since being arrested in September 1996 at Heathrow Airport. He was carrying £300,000 sterling when arrested.
He has spent much of his time studying law books relating to extradition and engages in a flow of correspondence with lawyers over his extradition. He has, so far, successfully fought the extradition case against him as far as the House of Lords. He is now pursuing a habeas corpus action suggesting that he cannot be sent back to Ireland as there is no British equivalent of the juryless Special Criminal Courts.
According to legal sources Mr Gilligan may be still able to pursue his action for a considerable time in the English courts but it is thought unlikely he will be able finally to prevent his extradition. One source pointed out that another prisoner, a South African, once fought an extradition case from Britain for eight years.
Mr Gilligan faces a charge of murdering Ms Guerin, possession and trafficking in cannabis and possession of firearms.