A former garda sergeant tried to pay prostitutes to get children as young as five for him to have sex with just a year after he had been released for a similar offence.

Kieran O'Halloran (48) offered two prostitutes up to €10,000 to source the children and asked one to organise "three or four children in a hotel room" for him to have sex with.

A court heard that he also asked a prostitute to get him a picture of a new-born baby with their genitals on view.

O'Halloran pleaded guilty at Dublin Circuit Criminal Court to inciting the women "to organise or knowingly facilitate the use of a child for the purpose of sexual exploitation" in October 2005 and April 2006.

Gardai had begun investigating him after one of the prostitutes tipped them off because she was disgusted by the requests. O'Halloran, of Liffey Court, Clane, Co Kildare, and Westminister Park in Foxrock, Dublin, was jailed for three years on 2003 for an almost identical offence and a 20-year post-release supervision order was also imposed.

Detective Sergeant Kevin Daly told prosecutor Fergal Foley that O'Halloran went to a brothel on Wolfe Tone Street, Dublin, in October 2005. He got a prostitute and asked her to get him an eight or nine-year-old girl.

He told her he wanted to "f***" the children and offered her €1,000 for every one she could get him.

He also asked her what was the youngest girl she could get and said he'd like to get three or four children in a hotel room. He also told her he had downloaded child pornography from the internet.

Before he left he claimed he wasn't serious about the request, but later phoned the woman a number of times repeating it.

The woman was "disgusted" and saved O'Halloran's phone number under "pervert" before giving it to gardai.

She made a detailed statement and a identification parade was organised but she was unable to pick him out. Gardai were forced to release him but continued monitoring his mobile phone.

In March 2006, O'Halloran visited another prostitute in a flat in Harold's Cross after reading her advertisement in a magazine. He asked her to get him girls from eight-years-old but "no older than 11" because he wanted an "innocent face".

He said that when she got the girls he wanted the prostitute to show them how to give him oral sex before leaving him alone with them.

He asked her if she had any friends with young children and said he liked to watch girls as they leave school. He also suggested he had visited other countries such a Thailand to abuse children. He later sent her several text messages repeating his request but this time offering her €10,000 for a "five or six-year-old child."

O'Halloran visited her again in April and this time brought a child pornography DVD with him which he showed to the prostitute and her partner. It featured an Asian girl, about 12-years-old, performing oral sex on man. He visited her a third time that month and again requested a girl under 13 to have sex with. Since the first incident in October gardai had been monitoring his phone traffic and were able to track down the prostitute who made a full statement. Gardai arrested O'Halloran in June 2006 and searched his Co Kildare home but found nothing of relevance.

Det Sgt Daly said he was very co-operative and admitted visiting the women but said he never intended to harm any children and that it was part of a "sexual fantasy".

O'Halloran had been in the gardai for 22 years and held a command post for 12 months in Croatia while working for the United Nations. Gardai said he had been "exemplary" in his role but resigned when the initial charges came to light in 2001. Defence counsel Luan O'Braonain denied his client ever travelled abroad for child abuse and said gardai could find no evidence of such travel.

He said O'Halloran was a recovering alcoholic who had been abused as a child.

Referring to the 20-year post-release supervision, Mr O'Braonain said: "Whether the regime was sufficient in its monitoring are questions I don't have the answer to."

He noted his probation report stated he was at a "huge risk of reoffending". Detective Inspector Paul Mulloy gave evidence that O'Halloran had some contact with the probation service following his release in 2004 but he didn't know how much.

Judge Katherine Delahunt demanded to know how much interaction he had with the probation service following his original release.

She said: "I want to know exactly what the engagement was. He says he engaged with them, I want to know if they engaged with him."

The judge adjourned sentencing until March so gardai could interview probation officers about their supervision of O'Halloran and she remanded him in custody until then.

Belfast Telegraph