Three-year-old Madeleine McCann’s disappearance shocked the world in 2007 when she vanished from her family’s holiday villa at Praia da Luz, Portugal.

Now, 13 years on, authorities believe they could be nearing the final heartbreaking chapter that closes the case.

Christian Brueckner, 43, aborted his parole bid on Wednesday as German police dug up a garden near his former home in the northern city of Hannover.

A small excavator was used to clear the allotment where police sifted through dirt and investigators also flew a drone over the property, in what could be the final stages of a marathon investigation into Madeleine’s disappearance.

Police removed the privacy screens that had been erected around the site on Thursday morning (Australian time), signalling an end to their search of the garden.

A 2018 police mug shot of Christian Brueckner. Photo: Milan Police

German sex offender Brueckner is serving time in prison for drug offences and the rape of an American woman in Portugal.

He is the primary suspect in Madeleine’s disappearance, with German officials last month revealing they believed she is dead.

Brueckner is a prolific burglar, rapist and has been convicted for past offences against young girls.

He was born in Germany in 1976, but little is known about his upbringing.

Court documents from a 2006 conviction for fuel theft reveal a social worker’s assessment of his history.

“He has an unstable past with no family roots and he is a loner. He has an errant past,” the social worker said.

In 1994, when he was just 18, Brueckner molested a six-year-old girl in Bavaria, only stopping when she began to scream and cry.

He fled Germany and only returned in 1999 to serve a two-year youth custody sentence for the crime.

A  mugshot of Brueckner taken in 1999

He went on to commit more offences against young girls.

In 2017 he was convicted of sexually abusing a child in Germany and was sentenced to 15 months in prison.

Then in 2019, he was sentenced to another seven years in prison for rape of a 72-year-old American woman in Praia da Luz in 2005.

But it is known he was in the same seaside Portuguese resort town as Madeleine when she went missing.

Brueckner was living a transient lifestyle and working in a restaurant and doing odd jobs in 2007, and friends say he used to drive regularly between Germany, Spain and Portugal.

A recent documentary aired by Germany’s Spiegel TV included an interview with a friend, identified only as Bjorn R, who said Brueckner would brag about stealing things from tourists.

“Alcohol sometimes loosened his tongue. He said that he was in Portugal and he got in everywhere and stole cameras,” Bjorn R said.

“In order not to be recognised where there were cameras, he took off his clothes and put on diving goggles so he wouldn’t be recognised.”

Brueckner’s van was spotted in the area.

Brueckner’s distinctive yellow and white VW Camper van was spotted in the Praia da Luz area before Madeleine vanished and he is believed to have dated a woman in the town on and off for years.

Pictures of the van that served as his home were released by German police after he was named as the prime suspect.

It’s believed the van, or a 1993 Jaguar XJR6, which he has also been linked to, were used in the disappearance of the child.

Last week, a former ambulance driver who met Brueckner and saw the van told Spiegel TV: “He told me, ‘I can transport children, kids, in this space. Drugs and children, you can transport them in this van. It’s a safe space in the van. Nobody can find them. Nobody can catch you’.”

Authorities suspect there is still someone, yet to come forward, with information about whether these vehicles were used to kidnap Madeleine.