UPDATE 9.30am: Police searching bushland at a site in Binningup, north of Bunbury, have confirmed they have found a body.
Police are yet to confirm if the remains belong to murder victim David John Houston.
"Major Crime Squad detectives investigating the alleged murder of David Houston located remains at a clandestine grave site overnight in the south-west of the State," police said.
"At this time there has been no formal identification made and a post-mortem examination will be conducted as soon as possible."
The East Perth Magistrate's Court was evacuated yesterday morning after a caller threatened to blow up police stations in a bid to free a man accused of Mr Houston's murder.
Sam Jacob Walker, 26, was due to face court yesterday morning charged with the alleged murder of the Hilton man.
At 10.30am on Saturday, the court was told by police prosecutor Sgt Steven Balcombe that the lockup had received a call saying if Mr Walker was not released on bail, police stations around the State would be "blown up".
Magistrate Richard Bromfield told the court that if anyone in the public gallery wanted to leave they could, but the session would continue.
A court orderly later told the prosecutor no more detainees would be brought up from the lockup because of the threat. The court was adjourned and the building was evacuated.
While the building was locked, the court resumed and Mr Walker's case was heard. Members of the public gallery and media were not allowed to re-enter the building while Mr Walker's case was in session.
Mr Walker was remanded in custody and is expected to reappear at the Stirling Magistrate's Court on June 6.
There were emotional scenes outside the courtroom earlier yesterday as Mr Walker's mother sobbed and was comforted by his father.
She said she was devastated and the family were "trying to process it". Both parents asked not to be identified by name.
Mr Walker is the third person to be charged over the death of Mr Houston.
Jonathan Robert Lee, 23, and Amanda Jane Kelly, 19, appeared in court on Thursday charged over the alleged murder and were remanded in custody.