Matt Mullaney, from Massachusetts, disappeared from Florence in February 2003 after visiting an Irish pub with some friends. There have been several sightings of the 23-year-old in Ireland since he went missing. His parents, Terri and Michael, are convinced that he made his way from Italy to Ireland.

"Matt was always very proud of his Irish heritage and we are convinced that he is in Ireland, " Terri Mullaney told the Sunday Tribune this weekend. "He even got a flaming shamrock tattooed on his back."

There have been three reported sightings of Matt in Ireland over the past three years, most recently last July, when an Irish couple contacted gardai claiming they had spent the afternoon with the missing student in Kinsale, Co Cork. The couple said that the man introduced himself as "Matt from Massachusetts" and said he was travelling around Ireland.

Others claim to have met Mullaney in pubs in Galway and Dublin, while a man resembling Mullaney told tourists in Liverpool and Amsterdam that he going to visit Ireland.

Terri Mullaney believes her son travelled from Florence, where he was studying art, to Amsterdam and from there through England and into Ireland. She has pleaded for anybody with information as to his whereabouts to contact gardai, and has put up a reward of 63,000 for information that helps the family get in contact with Matt.

"We can't explain why he has not been in contact with us, " she said. "He always stayed in touch with friends and family and had emailed us and talked to us on the phone shortly before he went missing. He had told us that he was not happy in Florence because the art course he was studying was not working out."

In the early hours of 1 February 2003, Mullaney was spotted talking to a group of friends outside The Lion's Fountain, a popular Irish pub in Florence. That was the last time he was seen in Italy and he has not contacted friends or family since.

When Terri and Michael travelled to Italy later that month in order to pack up their son's belongings, they found that none of his clothes were missing and his passport was still in the apartment.