A forensic archaeologist has told an inquest it was "extremely likely" a man's body found in a stream was "deliberately concealed".
Jamie Perkins, 41, was found dead with multiple injuries in Gilfach Goch in Rhondda Cynon Taf on 1 November 2017.
Despite the arrest of two local men and a £10,000 reward, no-one has been convicted of his murder.
Forensic archaeologist Alastair Vannan told the Pontypridd hearing he had examined police video and photographs.
He said Mr Perkins' body was partly covered with soil and vegetation, including dried bracken and fern.
Mr Vannan said large clumps of soil were also discovered on and around the body rather than thin horizontal bands of soil which he said would have been expected if the concealment was the result of a natural process such as a flood.
Mr Vannan said the distribution of the soil and vegetation in the area around Mr Perkins' body was not consistent with it being carried downstream naturally.
"There was a considerable quantity of fibrous vegetation on the body. It is extremely likely that this was a formal concealment," he told the inquest.
Earlier, the inquest heard from Amoret Whitaker, one of the UK's leading forensic entomologists.
She said she had examined the larvae laid as eggs from bluebottle flies found on Mr Perkins' body.
Dr Whitaker said bluebottles or blowflies usually lay larvae very soon after a body is deposited in a location.
She told the hearing after examining the samples sent to her by the pathologist she estimated they had been laid on Mr Perkins body around the evening of 8 October and the morning of 9 October 2017.
The last confirmed sighting of Mr Perkins was on 8 October.
The hearing was told there had been claims Mr Perkins was seen alive between 8 and 16 October.
Dr Whitaker was asked if her examination of the flies could allow for that.
She told the hearing "I would be a little surprised by that."
The inquest heard police examined 188 days and 19 hours of CCTV footage in a bid to find out more about Mr Perkins's last known movements.
The court was shown photographs taken of him at a house in Heol y Mynydd, in Gilfach Goch, where friend Carl Webber lived.
The images were taken on 8 October, and it was the last time he was seen alive.
CCTV cameras in a neighbouring house captured him walking past, wearing a blue jumper with the word Duffer on it.
The piece of clothing has never been found.
Mr Perkins was reported missing by his father the following Thursday, and originally classed as a "medium risk" by police.
But that was escalated to a high risk by officers a week later.
Det Con Sharon Wood confirmed his body was discovered by a man walking with his family at Bog Lane in Gilfach Goch on 1 November.
The inquest continues.