Leading HIV and AIDS charities have raised "serious concerns" over the prosecution of HIV-positive people who have unprotected sex with non-sufferers.

Campaigners have demanded the "highest standards of proof" before a case is brought against a sufferer for the reckless transmission of the virus.

It follows the prosecution of Mark Devereaux, who had unprotected sex with four different women across the north-east of Scotland, despite knowing of his HIV positive status for 14 years.

One of his victims found out she had contracted the virus when she was three months pregnant with twins, and subsequently had an abortion. However, the other three women were not infected.

The 41-year-old chef, who lives in Dundee, pled guilty to four counts of culpable and reckless conduct at the High Court in Edinburgh on Tuesday. He was remanded in custody to await sentence.

However, HIV Scotland and the National AIDS Trust have now expressed concerns that the case could lead to further prosecution. They believe Deveraux is the first person in the UK to be convicted of exposing someone to HIV without spreading the virus to them.

Activists say it is wrong to prosecute when no transmission occurs, arguing that adults who engage in unprotected sex know they are exposing themselves to health risks.

National AIDS Trust Chief Executive, Deborah Jack, said: “It is totally unjust to single out people with an HIV diagnosis for punishment for unprotected sex – we all need to be wiser and safer, looking after ourselves and those we have sex with.

"Most HIV transmissions are from people who have never had an HIV test. We recommend that the Scottish Executive change the law so that people with HIV cannot be charged with culpable and reckless conduct if no transmission took place.”

The trust also argued that exposing someone to the HIV virus is not a crime in England and Wales and should not be a crime in Scotland.

HIV Scotland also expressed worries about the case.

The charity's Chief Executive, Roy Kilpatrick, said: "We are particularly worried about the fact that prosecutions were brought in this case in respect of three sexual partners of Mr Devereaux who had not contracted HIV.

"We recognise that the primary motivation for bringing this prosecution must have been the actual transmission of HIV and that the prosecution would have felt it necessary to put the full context before the court.

"However, it would be alarming if the charges brought in this case open the door for future prosecutions in cases where no harm has been caused."

He said that bringing prosecutions where no harm had been caused would stigmatise people living with HIV and called for a clear statement of the Scottish prosecution policy.