Helen Gregory, 79, was found dead in her home on 24 January and police said she died as the result of a violent act.
On Friday morning, police began searching the landfill for things they believe were discarded by a person of interest several hours after her death.
Detective Senior Sergeant Tim Leitch said the investigation was continuing to piece together the events leading up to, and following, Gregory's death.
Specialist search teams were focused on a specific area of the landfill and were looking for "items that could significantly advance the homicide investigation".
"The investigation has uncovered significant evidence enabling the team to develop a clear understanding of the circumstances surrounding the death, and I am confident of a successful outcome," he said.
He urged anyone with information to contact police.
