A second officer, Ricardo Paiva, said Portuguese police were suspicious of the couple's 'merchandising' operation in the months after Maddie disappeared. The Madeleine Fund they set up sold wristbands and T-shirts publicising the case and used the money to support the search.
Mr Paiva said they should have faced prosecution for leaving their children alone, saying: 'People have been arrested for far less - even in the UK.'
Former Portuguese detective Goncalo Amaral wrote a book accusing the McCanns of covering up their daughter's death
He admitted that Mr Amaral's conviction about the McCanns' involvement had stopped police from investigating other theories.
But the only evidence the Portuguese police could amass against the McCanns was the reaction of sniffer dogs sent into the couple's holiday apartment in Praia da Luz, which smelled 'the scent of death'.
The performance of the dogs has been called into question after they also reacted to remains at Haut de la Garenne orphanage in Jersey, which were later found to be animal bones.
And we are all aware of the cover-up in Jersey...