A man remains in custody in connection with the death of a man crushed under the wheels of a double-decker bus during a row on a busy Dublin street.

A second person who was at the scene has also been identified and while he has been traced and interviewed, he has not been arrested.

The investigating team has still not identified the dead man, whose head and body were crushed when he fell into the road on the junction of Nassau St and Dawson St at 5.40pm yesterday.

Gardaí believe the victim had become involved in a row on the street and was punched or pushed, causing him to lose his balance and fall into the road as the 145 doubledecker bus was passing.

He fell under the wheels and was crushed to death as pedestrians looked on. The area was crowded at the time with the usual rush hour vehicle and pedestrian traffic added to with the evening Christmas shoppers.

Gardaí investigating the case have secured good quality CCTV of the incident and believe a number of homeless people and drug users were involved in the row during which the victim lost his life.

One of the group has been identified as the chief suspect whose actions apparently caused the victim to fall into the road. Gardaí tracked him down in Dublin city centre today and after putting him under surveillance for a period he was arrested.

He is currently being questioned at Pearse Street garda station under Section 4 of the Criminal Justice Act and can be held for up to 24 hours without charge.

The other people who gardaí believe were at the scene and have been identified are being treated as “persons of interest” by investigating gardaí rather than as suspects.

While reports suggest the dead man had been fighting with two people just before he fell to his death, the arrested man is now the prime suspect while the second man who has been traced and spoken to is for now being treated as a witness.

However, Garda sources stressed the investigation was in its early stages adding there may be more arrests. The man being detained now is believed to be homeless.

Gardaí have spoken to the driver of the bus and some of the passengers on it. The investigating team has also done a large amount of work in gathering descriptions and footage of pedestrians who happened to be in the area at the time and may make useful witnesses.

A public appeal for them to come forward is anticipated, possibly this evening.