The German man suspected of kidnapping and murdering British girl Madeleine McCann has refused to speak about the case, one of his lawyers told German television.

“Christian B. is not making any statements on the case for the moment and we ask you to understand that as his defence, we won’t either,” Friedrich Fuelscher told rolling news channel NTV.

German police raised hopes last Wednesday that the 13-year mystery over three-year-old “Maddie” could finally be solved when they revealed they are investigating a 43-year-old German man over her disappearance from the Portuguese holiday resort of Praia da Luz in 2007.

German police called the man a “murder suspect” who may have killed the young girl.

The suspect, named as Christian B. by German media, has a history of previous sex offences including child abuse and rape.

Currently held at Kiel prison in the north of Germany, the suspect is serving out a jail term for drug trafficking.

The suspect has had to be moved to an isolation cell for his safety, said Claus Christian Claussen, the regional justice minister of Schleswig-Holstein state.

He is not allowed to leave his cell unless accompanied by guards and not at the same time as other detainees to avoid attacks against him, said the minister during a hearing of the regional parliament.

Defence lawyers who had been charged with his defence have quit their mandate without giving a reason.

They have been replaced by a new team who have threatened lawsuits against their client’s acquaintances who described him as aggressive and suspicious.

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.

After Christian B. was identified as a new suspect, German police have said they are investigating if there is a link between the man and the case of another missing child in Germany.

The five-year-old girl named Inga from the town of Schoenebeck in Saxony-Anhalt in 2015 disappeared without a trace in the woods while on an outing with her family.