Forensic investigators and West Australian detectives have targeted a property near Mandurah as they continue to search for the body of drug trafficker Stephen Ramon Cookson.
Police were at the property in Golden Bay, 60km south of Perth, in large numbers, and officers were seen probing its grounds with long rods.
A search was also under way at nearby Silver Sands beach.
West Australian police had earlier confirmed Cookson's head washed up on Rottnest Island off the coast of Perth, amid reports detectives have quizzed those who may have dumped his remains.
A police spokesman said relatives of Cookson based in Victoria had now been informed of his death.
The remains of Cookson, 56, were discovered on the island earlier this month by an 11-year-old girl who was beachcombing with her family.
Police are continuing their investigations, which reportedly already include interviews with two men who may have come into contact with bags and property linked to the death of Cookson.
"Major Crime Squad are conducting an investigation into the circumstances surrounding Mr Cookson's death and detectives have spoken to several people and searched a unit in East Perth," police said.
Long associated with the seamier side of the racing industry in Victoria and WA, Cookson was convicted in WA in 2000 on one count of being in possession of a quantity of heroin with intent to sell or supply.
He unsuccessfully appealed that conviction all the way to the High Court, where the former law student chose to represent himself.
In 2005, Cookson was fined $5000 for improper conduct by WA racing authorities, namely assaulting and breaking the nose of former horse owner Peter Graham.
That fine was also appealed unsuccessfully.
A self-appointed "equine consultant", Cookson had been due to appear in WA's District Court this Friday on a charge of possession of methylamphetamine with intent to sell or supply.