A paranoid teenager who stabbed a “father figure” to death has been locked up indefinitely.

Father-of-two Simon Clark suffered a six-inch-deep fatal wound when the disturbed 17-year-old stabbed him through a gap in his front door.

Prosecutor Simon Myerson QC told Bradford Crown Court the defendant, who cannot be named, had put the knife into Mr Clark’s body to the hilt.

Mr Myerson said there was a disputed debt between the two men, who had cultivated cannabis together, and the teenager wrongly believed he was under threat of violence.

In August, the teenager went to 38-year-old Mr Clark’s flat in Liversedge, armed with a kitchen knife. The door was on a safety chain and he stabbed Mr Clark through the open door.

The victim died despite paramedics and police spending more than 45 minutes trying to resuscitate him.

Mr Myerson said the Crown accepted the teenager, who pleaded guilty last month to manslaughter on the grounds of diminished responsibility, was a young man with a psychiatric or psychological difficulty.

Bryan Cox QC, mitigating, said the defendant had been adopted when a few weeks old and presented behavioural problems from the age of 11 or 12 and had not received a great deal of therapeutic help.

Mr Cox said: “He came to regard the deceased as a father figure.”

Mr Cox said it seemed clear the deceased had told the defendant it had been necessary to destroy the cannabis crop they had an interest in, and demanded some compensation.

The defendant suffered from a conduct disorder, with an acute sense of rejection, an inability to control his emotions and a degree of paranoia.

Judge Jennifer Kershaw QC imposed a sentence of detention for the public protection and ordered a minimum of five years before he could be considered for release.

She said the defendant intended to kill or cause serious harm. He was disturbed, unhappy and ill equipped to control himself.

Judge Kershaw said: “I am satisfied the defendant presents a significant risk to the public. His difficulties have potential to lead to severe consequences to others.”