Police have established a crime scene at a home in Perth's east amid reports it could be linked to one of Australia's most high-profile cold cases.
Neighbours said police stormed a home in Kewdale about 7am on Thursday and took a man into custody.
The ABC, citing police sources, said the man in his 50s was being interviewed in connection with the Claremont killings of three young women in the late 1990s.
Jane Rimmer, 23, Sarah Spiers, 18, and Ciara Glennon, 27, vanished in Claremont in 1996 and 1997.
Ms Rimmer's body was found in bushland south of Perth in 1996, while Ms Glennon's body was found north of Perth in 1997. Sarah Spiers has never been found.
Despite extensive investigations, police have never charged anyone in connection with the case, codenamed Operation Macro.
Then, this week, police phoned the family of Ciara Glennon and told them there had been a breakthrough, Ten News reported.
At 6.30am on Thursday, Jim Sheffield was gardening in the back yard of his Kewdale home when he heard a "real loud yell" and what sounded like a scream.
Tactical police were swarming a neighbouring property, he said.
"I didn't think all that much about it," Mr Sheffield told journalists later in the day. "Came out about an hour later and there was a lot of police cars."
The man who was taken into custody has not been previously linked to the case, ABC reported.
He lived at the house with his daughter, aged in her 20s, for a number of years.
Vision from the scene showed forensic officers in the backyard of the home, where two blue marquees had been erected.
Investigators spent all day at the property and removed several boxes and large plastic bags from the house, which were brought to a mobile police command post on the street.
Police have so far declined to comment on the development, except to say the search at the home is "in relation to an ongoing investigation". Fairfax Media has contacted Western Australia Police for further information.
Speaking to radio station 6PR on Thursday night, Ten News journalist Rebecca Munro said sources had confirmed to her that the raid was "in fact linked to the Macro taskforce".
"This is a huge case," she said. "We've had it confirmed by a number of different sources.
"Moments ago we just saw a bunch of evidence come out of the house."
Australia's most notorious serial killer
Task Force Macro is Australia's longest-running and most expensive murder investigation.
It has investigated well over 3000 people and interviewed more than 500 people who were in Claremont on the night Ms Rimmer disappeared.
In 2008, detectives released previously unseen CCTV footage to media, which showed the 23-year-old exchanging a greeting with an unidentified man outside the Continental Hotel in Claremont on the night she disappeared.
It was midnight on June 9, and the hotel had closed. As Ms Rimmer leaned against a pole, a man approached her. She appeared to acknowledge him. He then walked out of view, the grainy footage showing only his back.
She remained on the footpath for many minutes, with people milling around her. The rotating camera panned away from Ms Rimmer and when it returned, she was gone.
The poor quality footage had been sent to US space agency NASA for enhancement years before its release, but NASA had been unable to improve it.
At the same time, police revealed more information about Ms Spiers and Ms Glennon.
Ms Spiers had called a taxi after 2am on January 27, 1996, when she left Claremont's Club Bayview. A witness reported seeing headlights nearby on Stirling Road, where Ms Spiers was thought to be waiting for the taxi. But the witness lost sight of the headlights after turning onto the Stirling Highway.
Meanwhile, when Ms Glennon was last seen by witnesses, she was talking to the occupant or occupants of a light-coloured vehicle that stopped on Stirling Highway on March 15, 1997.
She was seen leaning over with her hands on her knees as she spoke to those inside the car. Witnesses said when they looked back, the 27-year-old and the car had vanished. Other potential sightings of her on the highway that day made it impossible to determine if she had got into the car or not.
New evidence emerges
Rumours swelled in 2014 that detectives in Perth were close to an arrest. The rumours were swiftly quashed by police.
Then in December last year, the Subiaco Post reported that new clues appeared to have emerged, with detectives examining a link between the Claremont murders and the abduction and rape of a teenage girl in the year before the first murder.
The paper said police had forensic evidence linking Ciara Glennon's killer with a rapist who abducted a 17-year-old woman from a Claremont street then raped her in the cemetery in 1995.
The young woman had left Club Bay View shortly after midnight and was walking to a friend's house when she was abducted, taken to a cemetery, raped and released.
According to the Subiaco Post report last year, police also believed the killer used a mid-1990s white Holden Commodore VS series 1 to abduct and kill at least two of his victims, and had linked fibres found on Jane Rimmer's body to the upholstery of a car matching that description.
The Post also reported that new evidence showed this victim was tied up with washing line, not telephone wire as previously reported, and that the line was "impregnated with material used in screen printing".
The deaths of three women over 14 months in 1996 and 1997 sparked Australia's longest police investigation into what was dubbed the Claremont serial killings.
Ms Spiers went missing from outside a Claremont nightclub in January 27, 1996.
Ms Rimmer, 23, was abducted from Claremont in June 1996 and her body found in bushland south of Perth that August.
Ms Glennon, 27, disappeared on March 15 1997. Her body was found in bushland north of Perth 19 days after she was last seen in Claremont.
The story Major police operation in Perth linked to Claremont serial killings: Reports first appeared on WA Today.