Detroit police are searching for DNA samples of murdered union boss Jimmy Hoffa after an Irish-American criminal confessed to the killing in a book published in the US yesterday.
Frank "The Irishman" Sheeran, who died last December, agreed to co-operate with former Delaware deputy attorney general Mr Charles Brandt on condition that that the book be published after Sheeran's death.
In the biography, I Heard You Paint Houses, Sheeran admits to killing Hoffa at a Detroit house in 1975.
Sheeran, a mobster who served as an official in Hoffa's Teamsters Union, has long been a leading suspect in the killing. He told Mr Brandt, a former prosecutor, that he carried out the killing on behalf of crime boss Russell Bufalino.
Police are taking the claims seriously and hope Sheeran's confession could finally end one of the biggest mysteries in American crime investigation.
Sheeran, a committed Teamster enforcer, was close to Hoffa and describes him in the book as one of the two greatest people he ever met.
Oakland County prosecutor, Mr David Gorcyca, said police did not know if the floorboards in the house contained any traces of human blood, but said materials were being sent to the FBI crime lab for DNA testing.
Mr Gorcyca said that the floorboards did not appear to have visible traces of blood, despite claims by the Fox news channel that it had hired two former police officers who had found seven or eight small traces of blood on the floorboards.
On Monday, Fox ran details of Mr Brandt's book as well as details of its own investigation, which included computer recreations of the scene inside the house when Mr Hoffa was allegedly murdered.
Mr Hoffa was last seen on July 30th, 1975, at Machus Red Fox restaurant in suburban Detroit. He was there to meet Detroit Mafia enforcer Anthony Giacalone, who died two years ago, as well as Tony Provenzano, a leading New Jersey Teamsters official who was later convicted in another murder case.
Police say that at that time, Hoffa had hoped to settle a dispute with Provenzano in his attempts to regain his leadership of the Teamsters, a position he lost after he was jailed for mail fraud. President Richard Nixon agreed to release Hoffa from prison on condition that he not run for high union office.
In the late 1950s, Hoffa had been the main target of a Congressional committee trying to break links between organised crime and the labour movement.
In the book, Sheeran described Mr Bobby Kennedy, a prominent figure working for the committee, as "a son of a bitch" but said he was sorry to hear that Bobby's brother, President John F. Kennedy, was later assassinated.
Sheeran also claims that he killed New York mobster Joe Gallo while another Irish-American criminal, John "The Redhead" Francis, drove the getaway car. Gallo was murdered in a Manhattan clam house following a dispute with Mafia leaders.