The jurors in the trial of a man accused of raping his friend in Dublin have been told all the indicators are there to prove he suffers from sexsomnia.

His barrister also told them his non-memory of what happened when they shared a bed in September 2008 is a "classic symptom" of the condition.

In his closing address, Paddy McGrath, who is prosecuting, said the very idea of someone having sex in their sleep was highly unusual and lacking in evidence.

Defence barrister Hugh Hartnett disagreed and reminded the jury of the testimony of sleep expert Dr. Catherine Crowe, who concluded the alleged rape was more likely to have been an episode of sleep sex.

The alleged victim claims her friend raped with her while she slept beside him at an apartment in Dublin following a night out in September 2008.

The accused, who is 29 and denies the charge, says he only has a vague semi-awake memory of her asking if he was wearing a condom.

Mr. Hartnett described it as a "terrible thing that should never have happened" but asked the jurors to approach the case without emotion, and to give great attention to the facts and the expert evidence.

The jury will soon begin its deliberations.