Victoria Weldon A former policeman who claimed he was a black magic high priest was yesterday convicted of sexually abusing three youngsters.

John McFadden told one of his victims, a 12-year-old boy, that demons and spirits would kill him and drag him to hell if he told anyone about the sex acts.

The 42-year-old dressed in a black cloak and used a crucifix with a skull and crossbones and an onyx ring, which he claimed gave him power, to terrify the youngster into keeping the abuse a secret.

McFadden took blood, hair and semen from the boy, now aged 32, and burned them together in a bowl to initiate him into "the circle".

The victim, a former Marine, had told McFadden's trial at the High Court in Glasgow that he was abused by him almost every day for four years.

McFadden, of Bearsden, Glasgow, was found guilty of using lewd and indecent behaviour towards the youngster at a house in Kirkintilloch between 1988 and 1990 and sexually assaulting him on several occasions between August 1990 and 1992.

He was also convicted of using lewd, indecent and libidinous behaviour towards two other youngsters at the same address and at another nearby house on various dates between 1983 and 1990.

The same victim told the court McFadden befriended him after he joined a martial arts club run by him, and that the abuse began when McFadden, who still lived with his parents, invited him to stay overnight.

The victim, a father of one, said: "He started to get us into this black magic. He described himself as a high priest with this black magic circle.

"He said he could have out-of-body experiences and could talk to demons and spirits.

"One day he said he was going to initiate me into the circle and this became the main driver for my silence.

"He had a cast-iron bowl and he pricked my finger and put some blood in it. Then he took some of my hair and said that he had to have some of my semen and then it all had to be burned. I had to be naked and he had to be naked with this black cloak over him.

"I was thinking this isn't right' but I was told that, if I was to speak out, me and my mum and dad would be killed and sent to hell. I was terrified that either John would do something to me or these demons would come and do something bad. I basically went home and just cried."

The man also told the court that he tried to escape from the room one day after being asked to perform a sex act but was unable to unlock the door before McFadden grabbed him.

He also claimed that McFadden took naked pictures of him and filmed the abuse.

The victim said: "He told me that if he took pictures of me he might be able to use them as an alternative to him using me. I didn't want to do it, but I thought that it was my chance to get it to stop."

The court heard that the abuse came to an end when the man joined the Royal Marines and moved away.

Another man came forward in 1999 to complain that he had been indecently assaulted by McFadden when he was seven years old.

McFadden resigned from the police that year but was not convicted at that time.

He was finally charged several years later after two others came forward to report similar incidents.

When police searched McFadden's home they found a devil mask and two wands alongside sex toys and lubricants. He tried to claim that his victims were making up the abuse.

Judge Lord Matthews deferred sentence until next month for reports, and McFadden was remanded in custody.