Madeleine McCann abduction suspect Christian Brueckner is set be charged by the end of summer.
Detectives have told potential witnesses to be on standby to give evidence in a German courtroom.
The development comes a day before the 15th anniversary of Madeleine’s disappearance in Portugal in May 2007.
She vanished from her parents’ holiday flat in Praia da Luz while they dined with friends in a tapas restaurant.
Brueckner, 45, a convicted paedophile who lived in the resort, was named as a suspect in June 2020.
German prosecutors claim to have evidence that he abducted and murdered the three-year-old.
Brueckner was made an official suspect, or “arguido”, last month by Portuguese police still investigating Madeleine’s disappearance.
Her parents Kate and Gerry, from Rothley, in Leicestershire, welcomed the news, saying they have “not given up hope” that she is still alive.
Brueckner is suspected of raping an Irish tour rep in 2004 and exposing himself to youngsters in an Algarve playground.
Prosecutor Hans Christian Wolters said last October that he believes “a conclusion will be reached next year”.
Now we can reveal friends who knew Brueckner when he lived in Portugal have been told that charges could be imminent.
One former friend said: “I got a call from the Germans asking questions about a previous statement I made.
“They said I should be prepared to come to Germany, possibly at the end of the summer. They said they were hoping to charge Christian with something but didn’t go into any more detail.”
It is not known if the charges will be related to Madeleine’s disappearance or the other crimes he is suspected of in Portugal.
Wolters said the evidence they have against Brueckner left them “100 per cent convinced” he killed her.
He told Kate and Gerry: “We are confident we have the man who took and killed your daughter.”
Brueckner denies any involvement in her abduction and has declined to speak to police or prosecutors. He is serving a seven-year sentence in Kiel Prison, northern Germany, for raping a 72-year-old woman in Praia da Luz in 2005.
German prosecutors summoned Brueckner’s pals to give evidence against him during that trial in Braunschweig.
They included drifter Christian Post, who spent time with him in Praia da Luz.
Last month Post, who lives in Cambodia, said he is “100 per cent certain” Brueckner snatched Madeleine.
He claimed the German regularly broke into holiday apartments in Praia da Luz to steal cash and passports.
Brueckner mocked the case against him after being made an arguido and insisted his accusers have no evidence.
He wrote in a letter: “They had not even one proof I was involved with the McCann case. And they still don’t have it. I know why. Because they have no hairs or anything from Maddie [which] means that nobody can put anything like that in my stuff to find it.”
Kate and Gerry are preparing to mark the anniversary of their daughter’s disappearance tomorrow. The couple will spend the day at home with their teenage twins Sean and Amelie.
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