An elderly Brisbane woman missing for 12 days from inner-city Brisbane might have died in a bitter neighbourhood dispute over recycling.
Police are treating the disappearance of Lesley Trotter as a sudden death investigation as homicide detectives join the search for the 78-year-old's body.
Investigators on Friday said an extensive hunt led officers to believe she was dead after police initially conducted a missing-person search at Brisbane's Mt Coot-tha because Mrs Trotter was an avid hiker and bushwalker.
She last spoke to her family on March 27 and wasn't at her Toowong home when they visited the following day.
Detective Superintendent Andrew Massingham said police suspected Mrs Trotter died between midnight, March 27 and midday the next day.
"Unfortunately, investigations yesterday afternoon and late into the evening have led us to the conclusion that Mrs Trotter is in fact deceased," he said.
"The nature of that information specifically, I can't go into great detail. Suffice to say it is credible information we're acting on."
Police believe Mrs Trotter died close to her Toowong home. Crime scenes were established at her unit block and outside the complex.
More than 40 detectives are probing the disappearance, which might be linked to a dispute over recycling in the area.
"Mrs Trotter would often go to wheelie bins out the front of her residence or the neighbouring properties and remove recycling trash from general waste bins and transfer those into the correct bins," Det Supt Massingham said.
"We have not ruled out that this activity in some way is linked to her death."
Police said Mrs Trotter was well known in the neighbourhood for ensuring rubbish was put into the correct bins.
"Whether that's created some angst amongst the tenants, we're working through that at the moment," Det Supt Massingham said.
Adding to the family's distress was confirmation Mrs Trotter planned to leave the complex only to go missing before a final property settlement.
"This was a lady looking forward to the next chapter of her life. While she had some anxiety about moving into a retirement village, she was looking forward to that," Det Supt Massingham said.
"Something tragic has occurred on that Tuesday morning that's taken that opportunity away from her.
"At this stage, we do not have a location of Mrs Trotter's body, but we do have several lines of inquiry that may lead us to that location ... we do not know if the death is suspicious or not.
"It will take us some days to work through the evidence."
Mrs Trotter's family have been advised and are "deeply traumatised" by the tragic shift in the investigation, police say.
They had feared the worst after her mobile phone and wallet were found in the unit with her car still parked in her garage.
Det Supt Massingham said anyone with information or dash cam footage - particularly from between 5am and 7am on Tuesday, March 28 - should immediately contact police.
