Madeleine disappeared on May 3

One of the detectives leading the inquiry into Madeleine McCann's disappearance has told reporters her parents are not suspects.

Chief Inspector Olegario Sousa confirmed today that Gerry and Kate McCann are not under suspicion for their daughter's vanishing on 3 May and described them as "victims".

"The McCanns are not suspects. They are victims and witnesses," he said.

"I don't know where the newspaper got this information from but it is not true.

His statement comes as the McCanns prepare for a courtroom showdown with a newspaper that called them child killers.

Kate and Gerry McCann vowed to take the witness stand against journalists who accused them of giving their daughter a fatal drugs overdose.

They began libel proceedings yesterday, one week after Portuguese tabloid Tal & Qual ran the front page headline "Police believe that the parents killed Maddie".

It claimed detectives working on the case believe Madeleine died when her parents accidentally gave her too many sedatives to help her sleep while they went out to a nearby tapas restaurant with friends in Praia da Luz.

Mr and Mrs McCann, both doctors, have consistently denied giving their children any sedatives, and now they have decided to fight back against the wild allegations that appear daily in the Portuguese press.

Mr McCann said: "Kate and I have been deeply hurt by the report in Tal & Qual.

"The paper claimed we killed our lovely daughter Madeleine. This is without evidence or truth.

"The past 120 days have been horrific for us, our family and friends.

"We have tried to ignore some of the more ludicrous speculation but we simply could not ignore T&Q's report.

"We firmly believe that these sorts of unfounded reports distract people from the only thing that matters - finding Madeleine.

"The police have said time and time again we are not suspects. These are the facts."

The McCanns are being represented for free by a lawyer in Lisbon, Carlos Pinto de Abreu, and will not dip into the Madeleine Fund to pay for the case.

Mr Pinto de Abreu has filed a seven-page claim against Tal & Qual's director, Emidio Fernando, and reporter Catarina Vaz Guerreiro.

A friend of the McCanns said: "They will take it all the way if necessary and take the witness stand to defend their reputations.

"They are not doing this for money, this is a criminal action. They want their good name cleared."

Tal & Qual - which translates as "The way it is" - said Portuguese detectives "are almost absolutely certain that Madeleine was killed by accident by her parents".

The newspaper attributed its scoop to an anonymous source close to the investigation, and speculated about the sort of jail sentences someone might get for homicide by negligence and hiding a body.

Tal & Qual has stood by its story, with Miss Vaz Guerreiro saying: "I can't reveal my source but I have complete trust in them."

Mainstream Portuguese journalists, however, regard Tal & Qual as a sensationalist publication not known for having good police sources.