PORTUGUESE police and a public hungry for the truth might derail the investigation into the disappearance of British toddler Madeleine McCann, Lindy Chamberlain has warned.

Madeleine McCann, 3, vanished from her parents' room at a hotel in Portugal's Algarve region on May 3 as her two-year-old twin siblings slept and her parents ate at a tapas bar with friends nearby.

But her parents, Kate and Jeremy McCann, were last week named by police as suspects and returned to Portugal for lengthy questioning, but were released again two days later.

Police have handed their 10 volumes of reports and evidence to prosecutors, who have now submitted it to the investigating magistrate to consider any further lines of inquiry.

Lindy Chamberlain, now Chamberlain-Creighton, said there were many similarities between the McCann case and the disappearance of her daughter Azaria while on a family camping holiday to Uluru in August 1980.

Ms Chamberlain-Creighton has always insisted a dingo took nine-week-old Azaria from the family's tent.

She was convicted of Azaria's murder in 1982 amid intense public and media speculation, but was exonerated six years later.

"It's certainly looking like it (the McCann case) is having far more echoes of mine than I would wish on anybody," she told the Nine Network tonight.

"Answers are going to come from somewhere or another – whether it is the right answer is a very worrying problem."

There was immense pressure for police to solve the case, Ms Chamberlain-Creighton said.

"The public want answers, and if they haven't got them, they are going to invent them," she said.

"And the police are under pressure and have been trained to find answers.

"I certainly wouldn't want to go through it again and be in their shoes.

"There's nothing you can do, but I think as the public, we want to be careful not to run ahead."