The IRA informer and author Sean O'Callaghan has died at the age of 62.
It's understood Mr O'Callaghan passed away while a visiting a relative in Jamaica earlier this week.
From Tralee, the ex-IRA man came to prominence in the late 1990s when he turned on the Provos, and wrote best-selling book 'The Informer'.
The Kerry man was recruited at the age of 17, climbing the Provo ranks to become commanding officer of the IRA's southern command.
He claimed he then became an unpaid garda informer because he was revolted by the paramilitaries' violence.
After publishing his book, O'Callaghan claimed the IRA were determined to eliminate him - but he continued to make public appearances and speaking tours.
Speaking to the Belfast Telegraph newspapers in 2015, Mr O'Callaghan said: "I'm sure the Provos and dissident republicans would shoot me in an instant if they got the chance, so I keep looking in front of me as well as behind me.
"That's just how it is. It's part of the furniture. But I try and not make much of it and just get on with things."
O'Callaghan was jailed for life in 1990 after walking into an English police station to confess to the murders of UDR Greenfinch Eva Martin and Special Branch detective Peter Flanagan in the 1970s. He was freed under a Royal Prerogative in 1996.
It later emerged that he'd been a garda informer for nearly a decade and he said it was his tip-off that led to the seizure of a huge IRA arms consignment from America on board the ship Marita Ann in 1984.
He said he also told his handlers that he'd aborted a plan to kill Prince Charles and Princess Diana at a charity event they were attending in 1983.
A number of O'Callaghan's claims have been ridiculed by republicans. They branded him a fantasist, an allegation he dismissed out of hand.
In 2015, O'Callaghan wrote a book about one of the Easter Rising leaders - a man who had a massive influence on him while growing up in Kerry. The book was entitled 'James Connolly: My Search For The Man, The Myth And His Legacy'.
"Connolly certainly fascinated me. He would have been the biggest influence on me politically as I was growing up. He fired my imagination."