Mr Prendeville, 49, who presents Cork’s 96FM flagship daily morning show, was a passenger on Aer Lingus flight EI725 scheduled to leave at 10.15pm from London Heathrow to Cork on October 19 last.

As the jet taxied for take-off Mr Prendeville was seen to expose himself and masturbate as he sat in his seat. Mr Prendeville was seated in the front row of the aircraft facing two air hostesses. He was flanked by a female passenger to his right in a window seat and a male passenger to his left in an aisle seat.

When the aircraft was in the air an air hostess intervened and spoke with Mr Prendeville and the two passengers. Reports on the incident have been compiled by the crew of the Aer Lingus flight. These reports are in the possession of the airline’s head of security Mark Dunphy and form the basis of the airline’s investigation.

Yesterday, Mr Dunphy contacted the female passenger and told her that Aer Lingus has concluded its investigation. He said the airline would be making a formal complaint to gardaí.

Since the incident Mr Prendeville left a voice message on the telephone of the young woman who was sitting beside him, in which he said: “I just wanted to apologise to you for any offence that I might have caused you.” He said he had no recollection of the incident and that when he was told about it he was “shocked and horrified”. “I have no recollection whatsoever. I’m in shock, you know, I really am. I took some Nurofen Plus alright, I know that, for my neck. And as you know, with me anyway there was pints and wine and stuff and Jesus I don’t know where I’d begin to make it up to you,” he said on the voicemail.

Prior to the incident Mr Prendeville had spent the day in London as a guest of the Cork Convention Bureau. Cork Lord Mayor Michael O’Connell, Cork county mayor Jim Daly and Cork Convention Bureau (CCB) chairman Seamus Heaney led the delegation.

Mr Prendeville was one of a number of guests of the CCB who were entertained, prior to the flight, at celebrity chef Richard Corrigan’s Bentley’s Restaurant.

Mr Prendeville’s show is the most listened-to talk show on local radio in Ireland with almost 100,000 listeners each day.

Mr Prendeville declined several attempts to comment when contacted by an Irish Examiner reporter last night.