Madeleine McCann’s parents suffered “some of the worst harassment and bullying” seen during an investigation, a former top police officer has said.
Jim Gamble’s comments come as a new suspect emerged in Germany who is being investigated for her murder.
German police are treating the case as if Madeleine is dead, though the Met insists the investigation remains a missing persons inquiry.
German authorities and the Met have asked for information on Madeleine’s whereabouts and phone numbers, properties and vehicles linked to a 43-year-old German, who was said to be living in the Algarve between 1995 and 2007.
Gamble, who led the Child Exploitation and Online Protection Centre, and worked on one of the British investigations into the disappearance, said the McCann case was “pretty unique”. spoke about the case on the BBC’s Coronavirus Newscast.
Asked about his response to critics who complained about the amount of money put into the 13-year search, Gamble said he understood the attitude was “this is one missing child when there’s literally hundreds of thousands every year”.
He said, however, the truth is there are not that many, and children who go missing in the UK mostly turn up within about three days.
He added that a British child going missing on holiday abroad is “very different” to when a child goes missing at home.
“I think it has engendered a split in public opinion unlike any other case I’ve ever seen,” he told BBC’s Coronavirus Newscast.
Part of the split in public opinion has centred around Madeleine’s parents, who have been subjected to years of online criticism. They have previously admitted to being shocked by the abuse, saying they had seen “the worst and the best of human nature” since the campaign to find their daughter thrust them into the spotlight.
They have also endured a long-running libel battle against Goncalo Amaral, the Portuguese detective who led the initial inquiry into Madeleine’s disappearance, who alleged in a book that the girl had died in the holiday flat.
And in 2017, Mrs McCann blasted the “misinformation, half-truths and downright lies” that had circulated around her daughter’s case - although her husband has insisted that overall they had “been overwhelmingly seeing the better side of human nature” and received “fantastic support”.
Gamble said of the abuse: “Some of the social media content directed at the parents is among some of the worst harassment and bullying that I’ve seen in any case.”
The McCanns’ spokesman, Clarence Mitchell, said on Friday: “They certainly will be encouraged to know the appeal is yielding results already and hopefully within that there will be crucial bits of information the police can act upon.”
Gamble also told Newscast that the German authorities, the Met and Portuguese police “have more information than they’re actually sharing with us” to avoid diminishing evidence by putting words in people’s mouths.
Instead, by putting out information they have, they are hoping the public will be able to corroborate their evidence, he said.
German prosecutors said the suspect funded his lifestyle through crime, including break-ins at hotels and holiday apartments.
His Portuguese mobile phone was in Praia da Luz when it took a half-hour call about an hour before Madeleine was last seen.
Photos of properties linked to the suspect have been issued by police, as have images of a VW T3 Westfalia camper van and a 1993 Jaguar XJR6 that prosecutors say may have been used in the incident.