The mother of missing British girl Madeleine McCann was back in Portugal on Thursday for the start of libel proceedings against a detective who has written a book about the case.

Kate McCann and her husband Gerry are suing Goncalo Amaral in a Lisbon court for the book in which he argues Madeleine was killed accidentally and implicates her parents in her alleged 2007 death.

The McCanns have strongly denied the accusations and say the former inspector's claims have hampered the search for their daughter and exacerbated the anguish suffered by her relatives.

The McCanns' spokesman Clarence Mitchell said: "Kate and Gerry McCann remain very confident that they will win the case.

"They have a strong case against Mr Amaral. The matter is now in the hands of their lawyer as it goes through court."

Kate McCann could have been called as a witness but is not expected to give evidence.

Instead, a number of relatives of the McCanns will appear in the witness box to give evidence about the "damage" caused by Amaral's book which, they also claim, poisoned public opinion in Portugal against the family.

The family are seeking the equivalent of ??1 million (1.2 million euros, $1.6 million) in damages.

The McCanns have unsuccessfully tried to ban the book. It was taken off sale but is now back on the shelves.

British police said in August they were opening their own investigation into Madeleine's disappearance from a holiday resort on the Algarve in May 2007 while her parents dined with friends at a nearby restaurant.

She was just a few days short of her fourth birthday.

Her parents believe she was kidnapped and is still alive.