Three days into the search for the 78-year-old, Queensland Police confirmed several items were discovered at the Swanbank waste management facility in Ipswich on Thursday afternoon.
"At this stage, it remains unclear if the items are relevant to the investigation," police said in a statement, adding further examination is needed.
It could be the first significant breakthrough for investigators who are sifting through a large search area for any trace of Ms Trotter, who vanished from the inner Brisbane suburb of Toowong on March 28.
Her mobile phone and wallet were found in her unit and her car was still in the garage.
Investigators believe Ms Trotter was killed the night she went missing and her remains were hidden in a wheelie bin, which was compacted by rubbish collectors and freighted to two massive landfill sites.
The search began on Tuesday at the Swanbank facility on the outskirts of Ipswich after days of preparations to narrow down the search area.
"The area that we do have to search is quite enormous," Detective Superintendent Andrew Massingham said this week.
"There is some 3000 tonnes of general waste that we need to sort through."
Much of the work has been conducted by hand as the waste is exhumed from the landfill and tipped into 30cm deep trenches for investigators to examine.
Teams plan to comb through about 200 tonnes of rubbish a day, weather permitting, in a search that could take up to three weeks.
"This is very much a hand-and-eye type search, using rakes and indiscriminate-type equipment to sort through the general waste," Det Supt Massingham said.
Police hope to provide a further update on Friday.
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