The trial of a man accused of killing another man by punching him, causing him to fall under a bus, a year-and-a-half ago has begun at the Dublin Circuit Criminal Court.

Edward Connors, 30, of no fixed abode but residing at the time at a hostel in Aungier Street, Dublin, has pleaded not guilty to the manslaughter of 28-year-old Eoghan Dudley on Dawson Street on 6 December 2012.

The services of two sign language interpreters are being used in court because the accused is deaf and cannot speak.

The court heard that Mr Dudley lived in a flat in Newcastle, Co Dublin and was the eldest son of Noeleen Dudley, with an address at St Patrick's Cottages, Rathfarnham, Dublin who works in the Department of Foreign Affairs.

In its opening statement, the prosecution said that both the victim and the accused were heroin users and involved in begging.

Senior Counsel Tom O'Connell said the prosecution case is that Mr Connors punched Mr Dudley on 6 December 2012 at Dawson Street causing him to fall backwards onto the street and underneath a bus travelling to the city centre.