Forensic police officers will this week search for the blood of missing New Zealand woman Linda Sidon in the home she used to share with her son.
Ms Sidon was last seen on the Gold Coast in June 2009, and is believed to have been murdered.
The regional crime coordinator for the South Eastern Police Region, Detective Superintendent Dave Hutchinson, says Ms Sidon's son remains a person of interest in the case.
In August, officers named the 46-year-old's adult son as a person of interest in the case as they searched for her remains in the Numinbah Valley in the Gold Coast hinterland.
She was last seen at the Ashmore home where she lived with her son, who is now in his late 20s.
Her disappearance went unreported for more than a year, with her father eventually raising the alarm with police in New Zealand in late 2010.
At the time Ms Sidon's history of anorexia, anxiety and depression led police to believe she had committed suicide.
But two months ago, Det Supt Hutchinson said there was now a strong suspicion the part-time cleaner had been murdered.
"We have been able to confirm that she has not left Australia, she has not gone back to New Zealand and all inquiries would suggest that she has not left the Gold Coast either," he said.
"We believe that she has met with foul play."