The trial into the alleged murder of Ryan Merna is being held at Winchester Crown Court Wikipedia/Chris Talbot

A man was stabbed to death by his friend in a frenzied attack after his attacker falsely believed he had raped a woman, a court has heard.

Ryan Merna, 29, the son of the owners of a popular tourist attraction in Poole, Dorset, was knifed 32 times at his flat in the seaside town on 14 August last year.

Paul Taylor, 50, who was homeless and who Merna had allowed to stay in his home, is accused of his murder, which he denies.

Prosecutor Kerry Maylin told Winchester Crown Court that the pair met after both receiving treatment at St Ann's psychiatric hospital in Poole.

She said Merna, whose parents own Compton Acres botanical gardens, had asked Taylor to move out of his flat and had packed up his belongings.

The court was told that Merna later called 999 and could be heard saying: "Someone is coming at me with a knife. I need help."

A neighbour also called the police after hearing a fight.

"When police arrived, they saw Paul Taylor run away and sit on a piece of street furniture," Maylin told the court on Wednesday (19 July).

"Ryan was lying at the base of the communal stairs on his back and sticking in the back of his chest is a knife still in situ."

Merna suffered 32 stab wounds to his head and body, including a deep wound to his chest that caused a lung to collapse and another to his groin, the court heard.

The prosecution added that Taylor had accused his friend of the rape of a woman, but the alleged victim said that there had not been any sexual assault.

When Taylor was arrested, he was said to have told police: "I have killed a rapist. If he isn't [dead], will you let me back in there so I can finish him off properly. I really hope he is dead, I came here to murder him. He needs to pay for what he has done."

Officers said the accused "whooped and shouted" in celebration when he learnt of his friend's death.

Taylor also claimed Merna had stabbed him first and that he had retaliated in self-defense.

Although the defendant was said to have previously suffered periods of mental illness, he was assessed as sane at the time of the incident – but suffering a personality disorder.

The trial continues.