A cage fighter accused of blackmailing then murdering his ex-lover he met while he was behind bars told detectives he was “emotionally spent” and could not answer their questions.

Paul Robson, 50, denies murdering Caroline Kayll, 47, at her home in Linton, Northumberland and severely injuring a 15-year-old boy with whom she was having sex.

Newcastle Crown Court has heard Robson found out about her relationship with the boy and blackmailed her about it.

The prosecution alleged Robson, who met Mrs Kayll when she taught at HMP Northumberland where he was an inmate, drove from Glasgow to confront her in November at the home they had until recently shared.

Robson is alleged to have possibly stamped on her head and strangled her, as well as attacking the youth with scissors and a meat cleaver, and sprayed both with ammonia before he fled back to Scotland.

The defendant claims it was the boy, who cannot be named for legal reasons, who killed her.

When Robson was arrested and interviewed by police, his solicitor handed detectives a prepared statement.

It said: “When I heard about Caroline’s death I intended to arrange to surrender to the police. “I am emotionally spent, I am finding it very difficult to concentrate. “I never intended to kill anyone. “I cannot believe Caroline is dead, I cannot believe she is gone.

“This is like a nightmare, like a bad dream. “I cannot believe she’s not here, I am so tired and I am devastated.”

Robson said he had been at her house that night and they had argued before he was hit from behind, causing him to fall.

“I recall feeling something around my throat,” his statement continued.

“I was feeling all sorts of emotions.

“I remember being dazed and feeling sick and scared.

“I just felt like everything was unravelling.

“I may have asked for help, I just cannot clearly recall at this stage.

“When I learned Caroline was dead I contacted my solicitor.

“I feel broken.

 “My solicitor has arranged for me to be assessed by a psychiatrist. “I wish to be assessed as soon as possible to allow me to make sense of what has happened here. “In all the circumstances I am not in a position to sensibly answer any questions.”

Jurors were told Robson was interviewed for two hours but did not reply.

He denies murder, attempted murder and blackmail.

The trial continues on Monday.