'Tough going': gruelling search for Qld woman's body

Police are poised to begin the gruelling task of sifting through tonnes of landfill for the body of a Brisbane woman, as Commissioner Katarina Carroll warns the effort might take weeks if not months.

Engineers have attempted a "mammoth task" to isolate the rubbish collected from a single bin on March 28 , which is believed to contain the body of Lesley Trotter, 78, among the thousands of tonnes of landfill.

A team of police this week are expected to begin a physical search - by hand and piece- by-piece - to find any trace of her remains. 

"It might take days but, I've seen investigations like this in the past it might take weeks," the police commissioner said on Monday.

"They might even take months."

Despite the arduous task, recovering Ms Trotter's remains will be vital to the police investigation.

"When you get the body of a person, you then have a lot more information available to you in terms of evidence, the forensics et cetera, so it's incredibly important that we do as much as we can over the next few weeks to find her."

Ms Trotter vanished from the inner suburb of Toowong on March 28. 

The retired teacher's mobile phone and wallet were found in her unit and her car was still in the garage.

Days of searching became weeks and the hope of finding her alive faded as police confirmed they feared Ms Trotter was dead and treated her death as a homicide. 

Investigators had "strong evidence" Ms Trotter died the night she disappeared, police said. 

Her body was hidden a wheelie bin, which was collected the next day then taken to a Nudgee transfer station and dumped in a pit, along with rubbish from another 22 trucks. 

The rubbish was pressed in a massive compactor into huge blocks and freighted to landfill sites at Swanbank near Ipswich and Rochedale in Brisbane's south. 

Both landfill sites are official crime scenes as police begin a forensic search through mountains of refuse. 

It will not be a simple task. 

The day Ms Trotter went missing six B-double loads of garbage were moved to landfill sites. 

Rubbish collection continued for another 14 days, with another 300 truckloads disposed at the Nudgee transfer station alone. 

"It's going to be tough going," Ms Carroll said.

"They've done an extraordinarily good job of isolating the areas that have to have to be searched and now the tough job starts of searching those areas thoroughly."

It will be an agonising wait for her devastated family who have begged for privacy. 

"While the family continue to support each other at this difficult time, they ask to be allowed the space to grieve in private," the family said in a police statement.