The suspect linked to the disappearance of Madeleine McCann and three others may have evaded arrest in 2013 after a tip off was ignored.
German national Christian B, a 43-year-old convicted paedophile, was named as the prime suspect in the case of the three-year-old, who vanished in Portugal in 2007.
It has emerged that police received a tip he could have snatched the youngster after an appeal by British police on German TV in 2013.
A report was prepared for the Federal Criminal Police Office by local cops in his home town of Braunschweig.
But it is unclear whether the crucial tip ever reached British police.
Christian B has also been linked by police to the disappearance of a boy of 6 in 1996, also in Portugal, and a five-year-old girl in 2015, in Germany.
The authorities in Belgium have also linked him to the murder of a missing 16-year-old Carola Titze, who disappeared while on holiday in De Haan in 1996.
Christian B is currently eligible for parole having served two-thirds of his sentence for drug offences – but this is not automatic and German legal experts say it is unlikely to go through as he is under investigation for murder.
He has also appealed against a conviction for raping a 72-year-old woman in the Algarve in 2005, while he has not been charged with anything related to the Madeleine McCann case.
Police homed in on Christian B after he told a pal in a pub he snatched Madeleine, from the McCanns’ holiday flat in Praia da Luz, Portugal.
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