The suspicious disappearance of a fisherman at a remote island off Tasmania five years ago required a more thorough initial investigation by police, a coroner has ruled.
Coroner Olivia McTaggart said it was impossible to determine the exact circumstances around the death of Robert Charles Mansell, 42, who was reported missing on August 8, 2015.
Mr Mansell's friend, Joshua Kennedy, said the pair had been fishing on rocks at the mouth of a river on Flinders Island when he slipped into fast-flowing water trying to retrieve a snagged lure.
Mr Kennedy said in an affidavit he jumped into the water to try to save his friend.
But the coroner said Mr Kennedy's account of the morning contained problematic inconsistencies and anomalies.
An almost week-long air, land and sea search failed to find Mr Mansell's body.
In findings published this week, Ms McTaggart said several potentially suspicious elements required a more thorough police investigation.
"In hindsight, a more critical approach to the suspicious features of this case was required at an early stage," she said.
"(This) may have resulted in more evidence being obtained which could have clarified the circumstances of Mr Mansell's disappearance."
Mr Kennedy said he tried to call triple zero after Mr Mansell fell in the water but didn't have reception or credit.
Analysis undertaken as part of the inquest showed Mr Kennedy received phone calls at the same area later in the day.
Mr Kennedy said after trying to save Mr Mansell he started walking to raise the alarm because his car broke down.
A motorist who stopped after seeing Mr Kennedy said he didn't appear wet.
"It is quite plausible that Mr Kennedy had a physical fight with Mr Mansell leading to Mr Mansell falling into the water or being pushed into the water," Ms McTaggart wrote.
"If there was a fight between the men, it might have involved their respective relationships with (a woman) or simply have been the product of their characteristic drunken aggression."
The Director of Public Prosecutions determined in 2018 that no charges could be laid against Mr Kennedy.
Ms McTaggart said she was satisfied the case has now been investigated thoroughly and there is no other evidence that could feasibly be of assistance.
Mr Mansell died on August 8 on or in the waters around Flinders Island, she ruled.
Australian Associated Press