The partner of missing Sydney man Matthew Leveson is assisting police in a search for a body at the Royal National Park, south of Sydney, police have confirmed.

Michael Atkins has been helping police with their inquiries since Friday after being compelled to give evidence at an inquest.

Matthew Leveson, 20, was last seen outside Sydney nightclub ARQ with Mr Atkins on the night he disappeared.

Mr Leveson’s body has never been found.

In 2009, Mr Atkins was acquitted of murdering Mr Leveson after a trial during which he exercised his right to silence.

This morning, he was due to resume giving evidence for a sixth day at an inquest in Sydney but the hearing was adjourned until 2:00pm.

Deputy state coroner Elaine Truscott compelled Mr Atkins to give evidence and granted him immunity from prosecution.

This means any evidence he gives cannot be used against him in a criminal trial.

Police said detectives received information that led them to the Royal National Park this morning.

An extensive search is being conducted of the area and a crime scene has been established.