A person of interest in the disappearance of a Flinders Island man had pinned him on the ground and was choking him just a month before, an inquest has heard.

Key points: The coroner hears relationship between Mr Mansell and Mr Kennedy could be "quite toxic"

The coroner hears relationship between Mr Mansell and Mr Kennedy could be "quite toxic" Mr Mansell claimed he was pinned to the ground and choked by Mr Kennedy

Mr Mansell claimed he was pinned to the ground and choked by Mr Kennedy There was a suggestion that Mr Mansell, Mr Kennedy and a woman were in a "twisted love triangle"

Robert Charles Mansell, 42, was reported missing by his fishing companion, Joshua Kennedy, during a fishing trip on Flinders Island in 2015.

Mr Kennedy has been named as a person of interest in the inquest.

The inquest moved to Hobart this week and has heard from Timothy New, who worked for the Flinders Island Aboriginal Association for about 18 months before the disappearance.

Mr New told the inquest "Robbie" Mansell had rented a house on the island from the association and had also volunteered to work with him every week.

"He was a very reliable worker, he'd had a troubled past, but I found him to be very honest and he was always helping the community," Mr New said.

"There's more to a book than its cover. I think that he appreciated that I took him as he was."

Mr New described Mr Kennedy and Mr Mansell as "buddies" but said there were frequent fights over trivial things, which involved pushing and shoving.

"It was a very funny relationship — at times it was quite toxic," Mr New said.

"They seemed to get on quite well during the day … but in the evening if they were both drinking together then they'd often end up in arguments."

Concern over report Mansell had been 'pinned' and 'choked'

Mr New said he was concerned when Mr Mansell told him Mr Kennedy had "pinned him to the ground", in the living room of his home and was choking him.

Mr New said that was a month before Mr Mansell disappeared while fishing with Mr Kennedy.

Mr Mansell disappeared on a fishing trip from Flinders Island. ( Rose Grant )

He said he had advised Mr Mansell to stay away from Mr Kennedy, and had reported the incident to the manager of Flinders Island Aboriginal Association.

"Josh [Kennedy] had pinned Robbie [Mansell] to the ground and he was choking him," Mr New said.

"I knew they'd been in arguments, but this was the first time that Robbie was really concerned.

"Robbie used to tell me that on a few occasions, there was pushing and shoving, and one would end up going home from whatever premises they were at.

"But this is the one that stands out in my mind, because it was the most serious and the one that Robbie was concerned about."

Mr New said he did not know what the argument was about.

Suggestion two men part of 'twisted love triangle'

Lawyer Grant Tucker, who is representing Mr Kennedy in the inquest, put to Mr New that other witnesses had suggested the two men had been involved with the same woman.

"Various witnesses have come before this court and suggested they may have been [in] some kind of twisted love triangle between Mr Kennedy, and Stephanie Riggal and Mr Mansell," Mr Tucker said.

Mr New said he had asked Mr Mansell whether he was seeing Ms Riggal and he had replied "definitely not".

Ms Riggal was in the inquest, but is yet to give evidence.

Mr New said while Mr Mansell was not afraid of the water, he definitely was not a swimmer and, as far as he knew, he did not even own fishing gear.

"I wouldn't say that he was afraid of the water — I had seen him kayaking just in shallow water — but he certainly wasn't a swimmer," he said.

"I'd never seen him go swimming on the island."