Madeleine McCann's parents have been told they could receive more than £1m compensation from a former police detective who claimed she was dead.

Kate and Gerry McCann are pursuing legal action against Goncalo Amaral after winning a gagging order against the publication of his book.

Several thousand copies of the book have been handed over to the family's legal team, it is understood.

Mrs McCann returned to Portugal yesterday morning for the first time since being quizzed by police over her daughter Madeleine's disappearance in 2007.

After the couple met with their Portuguese lawyers and advisers in Lisbon, Mrs McCann said: “Our main worry, obviously, was people believing that Madeleine was dead.

“If people believe that she is not alive then people will stop looking for her. I just think that it's so vital and so fair for Madeleine that we don't give up on her, that we look for her. We're not going to stop.”

Mr McCann said there was no evidence his daughter is dead.

He said a team of private investigators is still working on the case — and is currently going through “hundreds of thousands” of pieces of information.

Legal proceedings are ongoing against Mr Amaral but lawyers have told the McCanns their search fund could be in line for a payout worth £1.2m.

Mr Amaral was involved in the initial investigation to find Madeleine but was later taken off the case.

In his book, The Truth Of The Lie, he claims Madeleine is dead and questions the McCanns' account that she was taken while they were eating with friends nearby.

Earlier this month a Portuguese judge banned further sale or publication of the book.