Falmouth man Trewen Kevern, who was jailed for life for the brutal murder of a family friend he called "grandad" has today lost his appeal against his conviction and will serve a minimum of 20 years in prison before he is eligible to apply for parole.

David Alderson, 72, was found floating face down in a pool of water at a disused copper mine near Bissoe, in January 2014. He had multiple injuries to his head and had been dragged into the pool, where he was held under the water until he died.

Last December, Kevern, aged 24, of Tresillian Road, and accomplice Kevin Cooper, aged 35, of Carharrack, were jailed for the murder at Truro Crown Court.

But Kevern, whose family had "adopted" Mr Alderson and who called him "grandad", continues to deny involvement in the killing. At the Court of Appeal today, he argued that his trial, where he put the blame on Cooper alone, was unfair.

But in a half-day hearing in London, Lady Justice Macur ruled that Kevern had no arguable case that his conviction should be quashed.

"This was a case where we have no doubt this applicant had all the points that could be made on his behalf made before the jury," she said.

The court heard Mr Alderson had died in a brutal attack and, afterwards, thousands of pounds in £50 notes stolen from his safe.

The prosecution alleged that his killers had agreed to murder Mr Alderson in order to get to his money. He was lured to the quarry, where he was attacked by one or both of the men. He was then dragged to the pool and held down until he drowned, before the pair began on an attempt to cover up the murder.

At their trial, Cooper and Kevern blamed each other for the murder, but were both convicted.

On appeal, lawyers for Kevern argued that he should have been tried separately to Cooper, who had refused to finish giving his evidence at the trial.

It meant Kevern's defence team had been unable to cross-examine him fully in order to show he was an "inveterate liar."

But Lady Justice Macur, sitting with Mrs Justice Carr and Judge Peter Collier QC, said the judge was entitled to continue the trial after Cooper refused to go back into the witness box.

The judge had told the jury specifically that they should not take account of any of the evidence Cooper had given against Kevern, she said. Cooper's claims against Kevern had been significantly "undermined" by other evidence in the case, she continued.

"The directions from the judge to the jury were meticulous in every respect," she added. "They cured any prejudice that this applicant suffered by reason of the inability to continue cross-examination of Cooper. We refuse permission to appeal against conviction."