Detective Inspector Darrin Shadlow said a farmer made the discovery about 5pm on Wednesday at his Bowlin Road property at Port Curtis, on the city's outskirts.

Inspector Shadlow said "just bones" were located, and forensic investigators were now trying to work out the gender and identity of the deceased.

The remains were found about 500 metres from where police two weeks ago located other items related to the suspected killings of Robert Martinez, 27, and Chantal Barnett, 28.

Inspector Shadlow said the farmer was not a suspect in the case.

The families of Mr Martinez and Ms Barnett have been notified of the find.

The pair were last seen in the Rockhampton/Yeppoon areas in late February or March 2013.

On Thursday, Inspector Shadlow said police would now scour the area around where the remains were found for more evidence. He said the process would be "painstaking".

"They will sift through all of that soil in that area to ensure we don't miss any bones that are there," he said.

"We're not going to speculate at all in relation to the identity of these remains. Suffice to say that they are in that similar area to where the vehicle was located last year as well as further items were located there two weeks ago."

Mr Martinez' wallet was found in the Bowlin Road area in April 2013 and six months later clothing believed to be Ms Barnett's was discovered in the Byfield National Park, north of Rockhampton.

Inspector Shadlow declined to say what police found on October 11 this, but said it was related to the investigation.

Four hundred people have been interviewed throughout the course of the investigation, he said.

"We believe that we have spoken to the person or persons responsible for the deaths of Robert and Chantal," he said.

Police have asked anyone with information to contact Crime Stoppers on 1800 333 000.