Police raised hopes last week that the mystery over the disappearance of three-year-old “Maddie” could finally be solved when they revealed they are investigating a 43-year-old over her disappearance from the Portuguese holiday resort of Praia da Luz in 2007.
The suspect, who was not named by police but identified as Christian B. by German media, has a history of previous sex offences including child abuse and rape, reported Spiegel on Friday.
Spiegel reported that the federal criminal police (BKA) had contacted police in Brunswick for more information about the suspect after receiving a confidential tip-off in October 2013.
But while calling the suspect in, police in their letter specified that it had to do with the “Madeleine McCann missing persons case” and “personal examination of Christian B”.
The letter would have given Christian B. ample time to destroy any evidence, the report said, quoting experts who consider the police's actions to be a serious mistake.
“This should not have happened and in no way corresponds to the usual procedure in such a sensitive case,” an experienced police officer was quoted as saying.
Police would usually gather information first before approaching a suspect, the report said.
Despite revealing last week that police had identified a suspect in the case, prosecutors have not called Christian B. in for questioning.
Such interrogation would take place only after an investigation is concluded so that investigators can put findings of the probe to the suspect, Brunswick prosecutor Hans Christian Wolters told national news agency DPA.
Madeleine went missing from her family's holiday apartment on May 3, 2007, a few days before her fourth birthday, as her parents dined with friends at a nearby tapas bar.
Her disappearance sparked one of the biggest searches of its kind in recent years.
Despite a wide range of suspects and theories about what happened, no one has ever been convicted over her kidnapping and no trace of her has been found.