A jury has begun deliberating in the trial of two brothers who claim a gang of Estonian men framed them for the murder of a Perth business associate.
Ambrose John Clarke, 54, and Xavier Gerard Clarke, 52, have faced an almost four-month re-trial in the West Australian Supreme Court charged with murdering 51-year-old Peter Davis.
Mr Davis was allegedly lured to a Malaga address in May 2011 under the guise of giving a business quote and was killed after intimidation and attempts to recover a perceived debt of about $300,000 through an unlicensed debt collector failed.
His body was found in the boot of his vehicle at the Great Eastern Motor Lodge the next day.
Prosecutor Paul Usher argued the father of four was bashed and suffered a "fatal cardiac event".
But Xavier Clarke's defence counsel Jonathan Davies claimed his client did not know Mr Davis, whose heart was "like a bomb waiting to go off".
Mr Davies blamed the assault on an Estonian gang, who were kickboxing and martial arts champions known for violence and intimidation.
He said the "standover men", who had previously worked casually for Ambrose Clarke, had their own financial reason to confront Mr Davis.
Ambrose Clarke's defence counsel Shane Brennan told the jury "innocent secondary DNA transfer" explained much of the evidence against his client, who had previously worked with Mr Davis.
Mr Brennan said if Ambrose Clarke was the killer he would be "the dopiest murderer that ever lived" to put incriminating items, including a page from Mr Davis' diary, in his unlocked filing cabinet.
He said the items were planted to frame Ambrose Clarke.
The jury heard Ambrose Clarke had started a franchise of Mr Davis' business but in 2009 Mr Davis suspected Clarke was stealing money, so they severed ties and Mr Davis complained to police.
Mr Usher said Ambrose Clarke believed he was owed money and by May 2011 he faced "huge financial pressure" so he turned to getting retribution by killing Mr Davis.
The victim's son found the car the next day and had his own car rammed by Ambrose Clarke's vehicle, which he was a passenger in at the time while wearing white forensic overalls, the court heard.
The jury retired to begin deliberations on Tuesday morning.