An appeal by police has generated almost 400 tips in the days since authorities said they were investigating a new suspect in the disappearance of Madeleine McCann.

The 43-year-old convicted German child sex offender, currently in prison in his home country, has been named in reports as Christian Brueckner.

A Metropolitan Police spokesman said: “The Op Grange team have had just short of 400 pieces of information through, in calls and emails.”

Operation Grange refers to the force’s active investigation, which the spokesman said police still consider a missing person inquiry because there is no “definitive evidence whether Madeleine is alive or dead”.

Meanwhile, German prosecutors are reportedly examining any links to the disappearance of two other children.

They believe Madeleine is dead after she vanished from an apartment in Praia da Luz, Portugal, on May 3 2007, while on holiday with her family, and are investigating the suspect over her murder.

German news websites have now reported that authorities have contacted the family of Rene Hasee, who went missing in 1996.

According to reports the then six-year-old, from Elsdorf, Germany, went missing from a beach while on holiday with his family in the Portuguese Algarve.

It comes as an investigation has been opened into whether the suspect was involved in the disappearance of Inga Gehricke.

She was five years old when she vanished from a forest in the Saxony-Anhalt region on May 2 2015.

Prosecutors in the northern German town of Stendal confirmed to the PA news agency they are probing possible connections between the cases of Madeleine and Inga.

But they said the man, who has been partially identified as Christian B by local media due to the country’s strict rules on the naming of criminals, is not currently a suspect.

He reportedly had a property in the town of Neuwegersleben, around 60 miles south-west of Stendal when she went missing.

Meanwhile, The Sun newspaper reported that a witness had identified the suspect as a man she saw acting suspiciously outside the McCanns’ apartment.

According to the newspaper, the British woman – referred to as a “credible witness” – said “that’s the man I saw” when shown a picture of the suspect.

The woman reported the sighting within hours of Madeleine’s disappearance, the newspaper added.

It comes after claims, originally reported by Sky News, that the suspect confessed to his part in Madeleine’s disappearance to a friend as they watched a TV news report on the case in a German bar on the 10th anniversary of her disappearance.

Scotland Yard said his name was already known to its investigation, but he did not become a suspect until after information was received as a “direct consequence” of a 2017 appeal.

The suspect is reportedly serving a seven-year prison sentence in the German port city of Kiel for the rape of a 72-year-old American woman in Portugal in 2005 after his conviction at Braunschweig District Court in December last year.

Der Spiegel reported his criminal record contains a total of 17 entries, including a conviction for the sexual abuse of a child in 1994 when he was aged 17, and a 2016 conviction for abusing another child and possession of child pornography.

It comes as Madeleine’s doctor parents Kate and Gerry McCann from Rothley, Leicestershire, welcomed the latest appeal in a statement saying: “We will never give up hope of finding Madeleine alive.”

Their 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.”

He added: “They are trying to maintain as normal a life as possible under the circumstances, continuing their medical work where necessary and bringing the twins up as best they can, while shielding them from all the attention.

“They wait to hear any developments from police.”