A man accused of murdering a Falmouth pensioner told "lie after lie" when questioned by police, a court has heard.

Trewen Kevern, 23, of Tresillian Road in Falmouth, and Kevin Cooper, 35, currently of HMP Exeter, both stand accused of killing former driving instructor David Alderson on January 17, 2014.

It is alleged that the pair took the victim from his flat in Old Hill to a disused mine at Wheal Maid near Carharrack, where he was beaten and had his head forced under water.

They then, the prosecution claims, returned to his flat and took £40,000 from his safe in £50 notes.

This afternoon Martin Meeke QC, acting for the prosecution, told jurors that Kevern had been questioned several times by police following the death of Mr Alderson, and had lied each time.

He said the first time Kevern was interviewed, as a potential witness, he claimed he had not been to the quarry with the other two men, who were travelling there on the pretext of an illegal gun deal.

He also claimed in that interview that he had been with Cooper that same evening when he went and stole money from a family of travellers called Lee, explaining that was where the cash had come from.

"But," said Mr Meeke, "nearly everything he told police in that interview was pure invention.

"He told lie after lie, but what he told police did lead to Cooper's arrest."

In a second interview in February, following the arrest, saying Cooper hadn't known he would be coming along with him and Mr Alderson.

Mr Meeke said: "That's a significant lie, because they planned to go out together that evening and they had the story of the Lee job as their reason for going."

He added: "He said that he was petrified of Cooper but all these lies were told at a time when he would have known that Cooper was safely locked up."

In a further interview, Kevern admitted to police he had been to the Wheal Maid site, but insisted he had stayed in the car until Cooper came back alone and "said that Dave was dead."

He claimed Cooper had told him to tell the Lee job story to explain how they had got the cash.

Police questioned the muddy state of both front seats of Mr Alderson's car, which would not have happened if Kevern had stayed in the car. Kevern then said that he had gotten out of the car after the fact and, when he had seen the body, Cooper had pushed him to calm him down.

Mr Meeke said: "There were only three witnesses to the events: David Alderson, who is dead, Cooper, who tells nothing, and Kevern, who tells lies.

He said Kevern and Cooper had exchanged plenty of text messages in the evening and the day following the murder, and also pointed to the fact Kevern had thrown his phone into Falmouth harbour.

He said: "The fact is Trewen is an accomplished and unashamed liar who sought from the first to try and hide the fact of his involvement in David Alderson's murder."

He added: "The crown's case is that these defendants took took Mr Alderson to the quarry that evening pretending there was going to be a gun deal.

"There never, ever was going to be a Lees job."

The defence for Kevern told jurors to bear in mind three things when they hear evidence: That Trewen Kevern didn't kill David Alderson or make a plan to kill him, that David Alderson was killed by Kevin Cooper, and that Kevern "told a lot of lies to the police and to his family" because "he was frightened of Kevin Cooper."

The defence council for Cooper also told the jury to bear in mind several items: Whether Kevern acted alone in killing Mr Alderson, and whether he did so because of the victim's "maybe sexist, maybe inappropriate" comments to Kevern's sister Tammy "and maybe other women."

Also whether any money was actually taken from Mr Alderson's flat, and whether Kevern's family and friends "got their heads together and conspired to exculpate Kevern and to blame Cooper."

The Crown Prosecution Service is seeking a conviction for joint enterprise murder, and the trial is expected to last for five weeks.