The court at the trial for the murder of 16-year-old schoolboy, Jack Frew, has heard claims that he exposed himself to his killer shortly before his death.

The high court in Glasgow heard from a psychiatrist that Mr Roy, 19, became furious because the deceased, Mr Frew, had exposed himself just before the incident took place at East Kilbride in May 2010, The BBC reported.

The schoolboy, the court heard previously, was found with 20 stab wounds, and his throat cut.

Psychiatrist Dr Rajan Darjee told the high court in Glasgow that Mr Roy said he had a sexual encounter with Mr Frew in January 2010, and was worried that his boyfriend, Christopher Hannah, would find out.

The court previously heard Mr Roy claim that he saw Mr Frew as a threat to his relationship with Mr Hannah, and that described him as a “sex pest.”

Dr Darjee said Mr Roy told him he had no memory of the events between producing the knife, and seeing Mr Frew lying, bleeding, on the floor.

The psychiatrist told the court: “Although he accepts it was him that killed Jack Frew he hasn’t any recollection of the incident.”

The accused, Mr Roy, has admitted stabbing Jack Frew, but denies murdering him.

Dr Darjee was asked by prosecutor Jennifer Bain whether Mr Roy qualified for a personality disorder, to which he said: “Mr Roy does not meet the criteria for personality disorder.

“There is evidence of some personality traits, but we all have some traits.”

He also said, with regards to the incident, that Mr Roy “struggles to accept he might act that way towards another person. He feels disgusted with himself.”

The trial continues.