A man has been convicted of the rape of a young woman in Aberdeen city centre.

Alasdair McDonald, 49, is facing a lengthy jail sentence for the violent attack on his 21-year-old victim.

The woman was targeted in Union Terrace Gardens around 3am on January 28, 2016.

McDonald overpowered the woman, forced her to the ground, repeatedly struck her on the head, restricted her breathing by seizing her nose and then dragged her into bushes and raping her.

At the High Court in Glasgow he admitted sexually assaulting the woman but denied that he had raped her.

But the jury did not believe the predator and convicted him of rape.

Judge Lord Arthurson told McDonald: "You have been convicted of an abhorrent sexual offence against a young woman who was a complete stranger to you."

The court heard that during the rape McDonald used excessive force to rip the crotch area of his victim's pants.

It was found some yards away and contained McDonald's DNA.

After the attack McDonald was initially spoken to as a potential witness and told officers: "I saw a black man walking away."

He denied that he was anywhere near Union Terrace Gardens.

But an extensive trawl of CCTV in the city centre revealed that McDonald was in the area at the time the rape was committed and DNA analysis conformed he was the rapist.

A police surgeon who examined the victim said that she had suffered "the worst internal injures" he had ever seen.

Lord Arthurson ordered McDonald, who is a prisoner in Barlinnie, Glasgow to be placed on the sex offenders' register.

He deferred sentence on him until next month at the High Court in Edinburgh.

Prosecutor Sheens Fraser said: "The accused has previous convictions, but they are not analogous.

"At the time of the offence he was unemployed and on benefits and living in Aberdeen with his identical twin brother."

During the search for the Union Terrace Gardens rapist a £5,000 reward for information was offered by Crimestoppers.

McDonald showed no emotion as he was led away to the cells after the guilty verdict.