Despite high hopes for a breakthrough following a BBC Crimewatch appeal in June, the enquiry has ground to a halt.
David Gilroy, a colleague and boyfriend of Ms Pilley, was jailed for life - with a minimum term of 18 years -in 2012 for her murder.
Detectives believe Gilroy killed the 38-year-old in the basement of their Edinburgh office and dumped her body in a forest in Argyll.
Following the Crimewatch broadcast, which recreated Ms Pilley's last-known movements, police received several phone calls.
Officers were initially optimistic that could lead to a breakthrough.
Tip-offs led to a remote spot near Minard, Argyll, but no further evidence was found.
Detective Chief Superintendent Gary Flannigan said: "All the work emanating from the Crimewatch programme from June has been followed through and there are no developments.
"We will continue to investigate the whereabouts of Suzanne Pilley's body, and anyone who knows something which may assist our inquiries is urged to contact Police Scotland."
Ms Pilley's father Rob said: "The door is ajar. It is not fully closed yet and that's what I would really like - to put closure on it for myself and the rest of my family."
Her mother Sylvia, speaking at the end of Gilroy's trial, said: "Justice has been done, but we felt so sad after it because we were never going to get her back.
"She's lying somewhere and nobody knows [where], as if nobody loved her."