A woman has been convicted of murder after brutally battering her well-off grandmother to death with a spade to ensure her inheritance.

Helpless Annie Garbutt, 77, who suffered from dementia, was repeatedly clubbed by Joanne Hussey as she lay asleep in bed.

A court heard that social services wanted Mrs Garbutt to be moved into full-time care and Hussey feared her grandmother's savings and investments would be swallowed up paying the bills.

Hussey, 33, of Grange Mount, Yeadon, had admitted unlawfully killing her grandmother but claimed voices in her head had told her to do it and she insisted she was suffering from a mental abnormality which diminished her responsibility.

But a jury of seven women and five men at Leeds Crown Court yesterday took only two hours, after an 11-day trial, to reject her claims.

Blonde, well-built Hussey, who pleaded not guilty to murder, bowed her head in the dock as she was unanimously found guilty.

Judge Scott Wolstenholme adjourned sentencing until next month so a further psychiatric report could be obtained on her.

But he told Hussey: "The only sentence that can be passed is one of life imprisonment."

Judge Wolstenholme said he would have to fix a minimum period she must serve before the parole board could consider her case. Hussey was remanded in custody until she is sentenced.

Postwoman Hussey, who had a string of affairs with fellow Royal Mail workers, attacked her grandmother at her terraced cottage home in The Clough, Mirfield, in May last year.

Mrs Garbutt died from multiple injuries. The court heard she suffered numerous facial fractures, internal head injuries and fractures to her larynx, ribs and breastbone, and at some stage Hussey had sat or kneeled on the widow's chest.

The court heard the murder was financially-motivated. Mrs Garbutt owned her cottage outright and had considerable savings, but social services were recommending costly full-time residential care which would have been funded from her savings, investments and possibly the sale of her house.

Hussey used a spade from her garden to batter her grandmother, then went to considerable lengths to cover her tracks, cleaning the spade and cleaning or disposing of her clothing.

Hussey, who has a severely disabled 11-year-old daughter, was described as "the apple of her grandmother's eye" but she had said she would punish Mrs Garbutt by not visiting her if she refused to give her money and she had planned to spend some of it on cosmetic treatment for her hair and teeth.

After the murder she asked her brother, Richard, and a close family friend to lie about her hearing voices.

Speaking after the jury returned its verdict, Detective Superintendent Andy Brennan said: "This was a particularly brutal and callous crime carried about Joanne Hussey on her grandmother while she was asleep in her own bed.

"Hussey went to great lengths to conceal her involvement in this crime by attempting to forensically clean her car, clothing, the scene and the spade used to kill Annie.

"However, due to some methodical and painstaking police work by the detectives who were dealing with Hussey and the team of scientists at the Forensic Science Service at Wetherby, Hussey's criminality soon became clear to those who were hunting for Annie Garbutt's killer.

"As the investigation developed, a clear picture emerged of Joanne Hussey: Firstly, she was an accomplished liar and for a number of days quite brazenly denied any involvement in her grandmother's death until all of the evidence became overwhelming clear to her that she had no where to turn.

"Secondly, she would stop at nothing to avoid being prosecuted and ultimately convicted, by attempting to get her family and friends to tell lies to the police on her behalf."