The circumstances in which a tourist lost his finger on St Patrick's Day in Dublin are being investigated.

Guy Wallace, a 17-year-old from England, told gardaí that he was attacked by a group of men and his finger was severed in the attack.

So far gardaí have only established that Mr Wallace was at a fast food outlet in O'Connell Street on St Patrick's night and that he was the victim of a minor assault there.

It is understood he was headbutted but that he did not fall. A number of gardaí on duty on O'Connell Street witnessed the attack and tried to come to his aid.

However, Mr Wallace ran away down a side street.

He was subsequently found on Cumberland Street in the north inner city, by which time he had lost his finger.

Gardaí have not ruled out his story that he was attacked by a group of five men, but they also are examining the possibility that he could have caught his finger in something as he ran and severed it accidentally.

It is understood that Mr Wallace cannot remember many details in relation to the incident.

Mr Wallace underwent surgery in Dublin's Mater Hospital yesterday. His finger has not been found.

Mr Wallace is a pianist and a rugby player.