Australia police
Australian police arrested David Napier six weeks after his best friend was murdered REUTERS/David Gray

A gambling addict bludgeoned his best friend to death with a hammer and dismembered his body with a hacksaw in a crime inspired by popular US detective TV show CSI, a court has been told.

David Napier, 53, pleaded guilty to murdering Richard Andrews in his victim's home in Perth, Australia in August 2016.

Western Australia's Supreme Court heard how Napier used a hammer to attack and kill Andrews because he was "frustrated" when the 70-year-old refused to lend him AU$100 (£61, €67).

Prosecutor Bernard Standish said Napier left the murder scene but returned later with a hacksaw to dismember the body, cutting off the head and fingers to prevent identification and removing the arms and legs.

He also used an axe to disfigure his victim's face, the court heard.

Standish said Napier then stored the body parts in plastic bags in a shed at his home, dousing them with bleach to mask the smell. He later disposed of them over a six-week period in bushland outside Perth.

Only 70% of his victim's body has been recovered so far.

The court heard how Napier later told a psychologist he watched TV shows like CSI to get ideas about how to cover up the murder.

Standish said his efforts to avoid suspicion included forging Andrews' signature to ensure his rent was paid and telling his Calista neighbours his now dead best friend was on holiday.

When Napier was arrested six weeks after the murder he initially denied any involvement in his friend's death, but later confessed to officers.

He claimed he wanted the AU$100 to buy equipment so he could kill himself, but Standish said the true motive "was because of his parlous financial situation, because of his gambling addiction".

In a police interview Napier told officers: "I just killed one of my best friends, just for f*****g money, because of my gambling.

"I am guilty. I am a piece of s**t."

Napier's lawyer, Patti Chong, said her client now suffers post-traumatic stress disorder and has nightmares about Andrews.

He can hear his voice and constantly smells his dead body, Chong added.

Napier faces a life jail term and is expected to be sentenced on Friday (4 August).