A man has admitted murdering his elderly mother with a chainsaw while she was hanging out washing in her garden.

Robert Owens kicked, strangled and attacked his 75-year-old mother Iris Owens with the power tool in Ystrad Mynach, where the pair lived together near Caerphilly in Wales.

Cardiff Crown Court heard the retired history lecturer died from trauma to her head and neck. She also suffered broken ribs.

Owens, 47, admitted strangling and attacking his mother. He was due to be sentenced on Tuesday.

Prosecutor Christopher Clee QC said neighbours had seen Mrs Owens hanging out her washing before the incident at around 5pm on 3 May.

One neighbour, David Harding, said he heard someone calling out and then the sound of a chainsaw starting in the garden.

Cardiff Crown Court (Google Maps)

Owens rang emergency services at 5:21pm. Paramedics said when they arrived at the property they found Owens "very agitated" with blood on his hands and overalls.

Mrs Owens, a widow, was found lying on her back near a tree stump in the rear garden, with a cut to the left side of her neck. She was pronounced dead at 5.42pm.

The court heard that in the 999 call, Owens said: "Yeah, my mother just went mad. I was chainsawing some wood.

"She's in the garden now, please help her. She's gone mad, she's not breathing, she went f****** mad. I've got to give her the kiss of life but she ain't doing nothing."

He told a paramedic that his mother had "gone berserk" and "I'm going to jail".

The court heard Owens began living with his mother after separating from his wife in 2006.

Mr Clee described Mrs Owens as an "active and independent lady" who volunteered for charities and attended church and Welsh classes.

Friends described her as educated, charitable, kind and "full of life", the court heard.

One said her relationship with Owens was "very motherly", adding that he was "odd" and sometimes "needy like a child who wanted attention".

The court heard tests after the incident revealed Owens had morphine, heroin and cocaine in his system.

When asked about his medical history, Owens said he was a heroin addict.

Simon Laws QC, representing Owens, said he was remorseful.

"This was a close, loving and supportive relationship so to sit where he does today having done what he did is a very terrible thing," Mr Laws said.

"He would like it said on his behalf that there's not a moment of any day when he is not reminded of what happened. He is devastated by what happened in those few minutes of anger in the garden."

Mrs Justice Nicola Davies said she was adjourning sentence until next week to reflect on the "tragic and unusual case".