A jury has failed to reach a verdict in the case of a man who claimed he was acting in his sleep when he allegedly raped a woman.

The 29-year-old man conceded he might have had sex with the woman, but claimed he was suffering from sexsomnia at the time – a rare condition that causes people to carry out sexual acts while asleep.

After deliberating for eight hours and 15 minutes over a three-day period, the jury foreman indicated that jurors were deadlocked and unable to reach a verdict.

“We’re fairly far apart, I don’t believe we’re going to have an agreement,” the foreman told Mr Justice Patrick McCarthy at the Central Criminal Court. He added that he was “absolutely” sure they would not be able to agree, given more time.

Mr Justice McCarthy thanked the jurors for their time and excused them from further service for a period of 10 years. The case was adjourned until November 28th when the prosecution will indicate whether it intends to seek another trial.

The accused, who cannot be named for legal reasons, had pleaded not guilty to one count of raping the woman at an apartment in Dublin in the early hours of September 28th, 2008.

This was the man’s second trial. A trial collapsed last year due to legal issues just before the jury was due to start deliberating.

The trial, which lasted four weeks, heard the man and woman were childhood friends and were in Dublin attending a career fair.

On the night of the incident, the man and woman had been at Copperface Jack’s nightclub and he had consumed several drinks and a naggin of whiskey before they returned to a friend’s house to sleep.

During the night, she said she awoke to find the man having sex with her. She said there was a conversation about contraception in which he was responsive to her. He told her he would go with her in the morning to get the morning-after pill

She said he later admitted he had raped her and they both agreed he would get help from a Rape Crisis Centre. Several months later, she made a complaint to gardaí.

The man’s defence team presented evidence from two expert witnesses who said it was likely that he was suffering from sexsomnia at the time. Witnesses also said he had a family history of sleepwalking and he had groped or grinded against people in the past while asleep.

“He was in automatism due to his sleep disorder. He was unaware of what he had done,” Dr John Michael Shneerson, former director of a UK sleep clinic and author of ‘The Handbook of Sleep Medicine’, told Hugh Hartnett SC, defending.

He said that it was personal opinion that the accused “fits very well with sexsomnia”.

“He jumps through the hoops and fits the template very well . . . it doesn’t fit in very well with someone who was drunk, awakes and has sex with someone,” Dr Shneerson said.

“His actions afterwards were remorseful and guilty. He went to his GP and a rape crisis centre in order to try and find out what had happened. He didn’t try to cover it up, which is a typical reaction from someone with sexsomnia, because they’ve no awareness and no consciousness.

“If he had been a sexual predator it would be unusual, with being both sleep-deprived and having taken alcohol, to be able to stay awake to rape someone.”

The prosecution said alcohol intake was a more likely factor in the incident than sexsomnia and that the accused’s actions were not consistent with the condition.

Dr Harry Kennedy, a forensic psychologist, gave evidence for the prosecution that he questioned whether it was possible for a male to get an erection during non-REM sleep, the stage of sleep in which sleepwalking occurs.

“This is not the normal physiology,” the doctor said. He added that it might be possible for someone to have an erection while transitioning into non-REM sleep but that he would need to see a demonstration of this.

Dr Kennedy said actions during sleep were generally “very very simple” and directionless. Speech was incoherent and meaningless, he said.

He said the accused’s alleged actions, including pulling up the woman’s skirt and pulling aside her underwear, demonstrated “intact mental ability and therefore consciousness”.