A jury has convicted a man of causing serious harm to two former partners by infecting them with HIV.

It was the State's case that the 28-year-old man was aware of his diagnosis when he infected the women and that this amounted to serious harm. The court has heard it is the first case of its kind in the country.

The man, who lives in Dublin, cannot be named to protect the identities of the complainants in the case.

He had pleaded not guilty at Dublin Circuit Criminal Court to intentionally or recklessly causing serious harm to the two women on dates between November 2009 and June 2010.

After an eleven-day trial and just under four-and-a-half hours of deliberations, a jury of nine women and three men returned unanimous guilty verdicts on both charges.

The maximum penalty for the offence is life. Judge Martin Nolan remanded the accused in custody pending an application for bail.

He said he would sentence the man before the end of July.

Judge Nolan thanked the jury for the carrying out its duty. He said this was a pretty difficult case with unusual type of evidence.

In his closing speech to the jury on Tuesday prosecution counsel Dominic McGinn SC submitted that expert witnesses had said that all three parties had the same subtype and mutations of the virus.

Mr McGinn suggested that the complainants had "remarkably similar" accounts and said they used condoms with previous partners.

Counsel reminded the jury that it had heard condoms "if used correctly effectively stops transmission" and that oral sex does not lead to infection.

He said there was no evidence that any of the complainants' previous partners were HIV positive.

He told the jury that the man lied to the complainants' doctor about his positive diagnosis and "went through the charade" of being tested again for the virus in 2010.

"He knew full well he was HIV positive. He was advised about having safe sex. He admitted that to gardaí and he was given anti-viral medication and he didn't take it," Mr McGinn submitted to the jury.

Mr McGinn suggested that the accused was guilty on both charges against him because he acted recklessly and caused serious harm to the complainants.