A man who waterboarded his vulnerable flatmate after stealing £200 from his post office account has been jailed for five years.

Ryan Cartwright, 26, subjected John Campbell, 41, to the ordeal which saw him copying a torture technique used by CIA interrogators on suspected terrorists.

The High Court in Edinburgh heard how Cartwright tied Mr Campbell to a chair and placed a towel over his face. He then poured water over the towel which prevented his victim from breathing.

Cartwright then struck Mr Campbell in the groin with the wet towel before choking him.

Mr Campbell, of Knightswood, Glasgow, told jurors: "I was so scared. I couldn't breathe. It was terrifying."

Cartwright, of Clydebank, West Dunbartonshire, had pled not guilty to serious assault and robbery charges. However, jurors spent 80 minutes in deliberations before returning guilty verdicts to the two charges.

Mr Campbell, who suffers from anxiety, told the court he had known Cartwright for five months before the assault.

He said that Cartwright had moved into his flat in Knightswood just a few weeks previously.

He told prosecution lawyer Una Doherty: "I was scared of him. He would do dummy fighting with me. He would treat me like a punchbag. He used to stick a knife up to my face."

On the morning of May 24, Cartwright took a Post Office account card belonging to Mr Campbell and withdrew £200 from a bank machine in Anniesland Road. Cartwright then returned to Mr Campbell's flat and assaulted him.

Judge Lord Beckett handed Cartwright a five year sentence for the assault and a 12 month sentence for the robbery which will run concurrent to the prison term.

The judge told him: "You bullied a vulnerable man and subjected him to a variety of painful, frightening and humiliating assaults."