A magistrate has thrown out charges against five men accused of killing a prisoner at Port Phillip prison.
Mark Pollard, 48, died in hospital days after he was assaulted during an alleged robbery in his prison cell in February 2020.
Riyad Jamal Ahmed, 32, Abdulkadir Ali, 34, along with 26-year-olds Kiuna Leveni, Justin Ibrahim and Salah Abukar, were accused of unlawfully killing Pollard.
Prosecutors cited witnesses inside the prison who said Pollard was "jumped" in his cell, attacked from behind, and his shoes and wedding ring stolen.
"They were dirty dogs, five on one," according to one witness, who said the robbery was part of a plan involving all five men.
"That assault ultimately caused his death," the Crown said.
But defence lawyers for the five prisoners successfully argued the prison bashing did not cause Pollard's death, because he suffered underlying health conditions.
The court heard that after the bashing, a blocked artery cut off blood supply to Pollard's bowel, causing toxins from the dying organ to leak into his body and poison him.
Defence lawyer Patrick Doyle, acting for Abukar, argued the forensic evidence did not point to injuries from the assault contributing to his death.
"There is no basis to find blunt force injuries were a cause, let alone a significant cause, of death," he told the court.
Magistrate Andrew McKenna agreed, ruling the men should not face trial on the kill charges, because a properly instructed jury "would be incapable of accepting the cause of death as being attributable to the accused".
Mr McKenna said expert medical witnesses had not made the necessary causal connections between the bashing and Mr Pollard's death.
But he said the men could potentially face other charges linked to the robbery.
All five men are serving sentences for unrelated matters.
The hearing continues.
