Video footage has been published of an incident which appears to show former MMA star Conor McGregor punching an older man in the face.

The incident is understood to have taken place at the Marble Arch Bar in Drimnagh in Dublin last April.

The video, which appears to have been filmed on CCTV, has been published on the US website, TMZ.

It shows an individual resembling Conor McGregor approaching the bar and pouring drinks for a number of people sitting at the counter. One of the men appears to decline the drink and moves the glass away.

The video then shows the individual being punched in the face.

Following the incident, the man throwing the punch is escorted out of the pub by a number of people.

The timecode on the video suggests the encounter took place over six minutes on the afternoon of 6 April.

Gardaí confirmed to RTÉ News that they were investigating an "assault incident that occurred at a public house in Drimnagh.

"Investigations are ongoing in relation to this incident and no arrests have been made to date," gardaí said in a statement.

In March, Conor McGregor announced his retirement from Mixed Martial Arts.