An ex-Madeleine McCann cop fears that Christian Brueckner could be linked to at least three other unsolved child horrors.

Jim Gamble said Brueckner could be responsible for some of Europe’s most harrowing missing child cases.

Yesterday, detectives were “re-examining” the murder of German teenager Carola Titze, who was killed on holiday in Belgium in July 1996.

And German police are now looking into whether Brueckner is linked to the mysterious disappearance of Inga Gehricke, five, – in Saxony-Anhalt in May 2015.

Last night, the dad of a third child, Rene Hasee, age six, also demanded answers – nearly 24 years after he vanished from a beach in the Algarve.

Jim Gamble recently appeared as a guest on This Morning

Andreas Hasee told the Sunday Mirror that police contacted him after Brueckner was named as a suspect, adding: “I have no doubt Maddie and Rene’s cases are linked. The police are looking again at my son’s disappearance.

“He was a lovely boy, my first child, and I will never get over what happened. I think of him every day and imagine what sort of man he would have been.”

Rene, from Elsdorg, western Germany, was on holiday with his family in Aljezur, 25 miles from Praia da Luz, when he vanished on June 21, 1996.

René Hasee disappeared from a beach in 1996
René Hasee disappeared from a beach in 1996

He had been running ahead of his mother and stepfather during a walk on the beach when they lost sight of him. His clothes were later found, and authorities speculated that he drowned in an accident.

Police in Portugal failed to carry out any proper searches of the sea for two days.

Andreas said: ”They were convinced he went into the water, but I know in my heart he didn’t. He was taken. The police investigation was not through enough and I see the similarities with what happened to Maddie.”

Police in Belgium are investigating whether Christian Brueckner is linked to the death of Carola Titze

Last night, Mr Gamble – the former head of the National Crime Agency’s child unit –said Brueckner is a “driven sexual predator”.

He said: “When you’re tracking someone of this nature, what’s critical to remember is there’s never only one offence.

Madeleine went missing in 2007

“The nature of these people and the way they are driven towards offending, you don’t get a one-off offender.

“You can see is he has offended against girls and against older women. So he has no particular preference, he is a driven and motivated sexual predator.

“There is a huge likelihood they would have offended there multiple times.”

International police forces are liaising as more evidence comes to light after Brueckner was unmasked as the prime suspect in the disappearance of Maddie.