A man has described the chilling moment he cut off his partner’s head and flushed it down the toilet because she had “betrayed” him.

Dempsey Nibbs, 69, is on trial at the Old Bailey for the murder of Judith Nibbs, 60, his partner for 30 years.

Giving evidence today he explained how he confronted her in the living room of their home in Charles Estate, Hoxton on April 10, 2014.

Nibbs said he had intended to “slap her about a bit” because he believed she had been seeing another man and transferring his money to him, but said he did not intend to kill her.

After striking her with a padded bar and shoving it in her mouth he saw her eyes roll back in her head and thought she was dead.

“I was upset,” he said. “I started to call her every name under the sun – ‘you f****** traitor’, ‘you f****** snake, I’ll cut your head off’.”

His defence counsel Ian Henderson asked why he was saying these things.

“Back in the day you hanged murderers and cut the head off a traitor,” he explained. “She betrayed me.”

Nibbs then told the court he dragged her body out of the living room and into the hallway because he didn’t want the room “to be a mess”.

After placing her on a tarpaulin bag he used a knife from the kitchen to cut her head off, intending to flush it down the toilet. “It [the toilet] wasn’t big enough, obviously, that’s why I had to smash it up,” he continued.

Nibbs said he struck her head once with a hammer and flushed it before cleaning up the living room.

He then explained how he tried to shoot himself.

“I was trapped and there was no way out other than a bullet to my head,” he said.

Nibbs said he wrote a note and left some money for his son Kirk. He then placed documents, including bank statements showing money transfers, on Judith’s body for police to find, as an explanation for what had happened.

After dialling 999 he tried to shoot himself in the bath but the gun misfired so he stabbed himself once. At this point the police arrived.

Nibbs admitted he had been “snooping” on Judith, who he thought was having an affair, and had hired a lawyer. By February 2014 they were sleeping in separate bedrooms but Nibbs “always hoped” they would enjoy their retirement together as planned.

But he said that changed when he found bank statements showing a money transfer to the man he thought she was seeing. Nibbs thought she had transferred money from a £20,000 payout he had entrusted her with after he discovered it wasn’t in their joint account.

“All my hope was gone,” he told the court. “I suspected she was having an affair but the statement was proof.”

Nibbs told prosecutor Crispin Aylett that he had never asked Judith about the money, which he now knows was in a savings account. Mr Aylett explained the cash transfer to the other man was done as a favour and was not Judith’s money, or Nibbs’.

Doctors have said Judith was alive at the time of her beheading. When asked by Mr Aylett about that Nibbs said: “She looked dead to me.”

Nibbs claims he killed Judith Nibbs in self-defence. He denies murder and obstructing the coroner from holding an inquest by disposing of her decapitated head.

The trial continues.