Police officers dig and search a garden plot in Hannover, northern Germany, 29 July 2020. Police is working on the site in relation to the investigation of the Madeleine 'Maddie' McCann case. The English child disappeared on 03 May 2007, from a room where she slept with two twin brothers, in an apartment of a resort in Praia da Luz in the Algarve. Police searches garden plot in the Maddie McCann case, Hanover, Germany - 29 Jul 2020 - FRIEDEMANN VOGEL/EPA-EFE/Shutterstock
Police officers dig and search a garden plot in Hannover, northern Germany, 29 July 2020. Police is working on the site in relation to the investigation of the Madeleine ‘Maddie’ McCann case. The English child disappeared on 03 May 2007, from a room where she slept with two twin brothers, in an apartment of a resort in Praia da Luz in the Algarve. Police searches garden plot in the Maddie McCann case, Hanover, Germany – 29 Jul 2020 – FRIEDEMANN VOGEL/EPA-EFE/Shutterstock

German police investigating the disappearance of Madeleine McCann have discovered a sealed-off cellar after excavating an allotment site just outside Hannover.

Witnesses said on Wednesday they had watched as the BKA, the German federal investigators, lifted off a cement block covering the basement during the first day of digging at the council-owned site.

After discovering the underground cellar, officers led in a sniffer dog, which barked when it entered, the Telegraph can reveal. “The sniffer dogs were barking quite a lot in the morning,” said one person present.

Authorities began searching the site on Tuesday, in connection with the disappearance of three-year-old Madeleine. German police believe that she is dead.

The Braunschweig prosecution office, which is coordinating the investigation, confirmed to The Telegraph on Monday night that the operation at the garden had been completed. Spokeswoman Julia Meyer would not comment on whether any evidence had been found during the search.

Police use sniffer dogs at the site - AP
Police use sniffer dogs at the site – AP

Last month, Christian Brückner, 43, was named as the prime suspect in what German authorities’ are treating as a murder investigation. Brückner, a convicted paedophile, was living in the Algarve in Portugal when Madeleine went missing in May 2007.

German police claim they have evidence linking him to the case. While he was living in Hannover, he was convicted of two crimes.

By Tuesday evening, police in Hannover had dug a two-metre-deep hole in the ground at the centre of the allotment, with forensic tents erected next to it. The dig continued on Wednesday from 7am in a different area of the garden.

Cement and other heavy duty materials were seen being removed from the site in the town of Seelze, just outside Hannover. At least seven police vehicles including a truck were present at the cornered off plot.

Police watch on as the digger excavates the plot - AP
Police watch on as the digger excavates the plot – AP

Wolfgang Kossack, 73, who owns the plot next to Brückner’s former allotment, told the Telegraph that a man with two dogs lived in the run-down shed on the site in 2007, the same year Madeleine McCann disappeared.

He said: “I can’t tell you if it was the same guy. What I can tell you is that he was there with two dogs. One was small and brown the other one was large and black. He was there for between eight and nine months around about 2007. I went on holiday one July and when I came back he was gone.”

He and his wife had a few “uncomfortable situations” with the man. His dogs defecated in their garden, and the man’s car, a cream-coloured VW camper van, “stank of diesel”. Kossack recalled: “At first, he apologised but he became increasingly aggressive.”

That description fits that of the 43-year-old Brückner, who had two dogs while living in Hannover. While still in Portugal, he drove a white and yellow VW Westfalia camper van.

Residents living next to the five allotment plots said they were “disused and overgrown” and had been for years. The shed was falling apart.

Mr Kossack said: “It was more of a ruin than a house. He tried to do up the roof and insulate it and he seemed to sleep there from time to time. When he left he took down everything that he had built as he had to leave it as he found it.”

Another man, who lives across the road from the plot, said: “The people there were just normal folks who didn’t live there. They just came here to get away from the city.”

“I can’t remember anything about the people who were there, but there was a Volkswagen camper that would turn up now and again. It was white and red.”

Brückner was found guilty of two crimes during his time in Hannover. In 2010 he was charged with falsifying documents and ordered to pay a fine. Three years later, he was convicted of theft. He did not serve a prison sentence.

Shortly after, he left the city and went to nearby Braunschweig (Brunswick), where prosecutors are running the investigation against him.

While in Hannover he lived in a high-rise apartment block in Linden, a neighbourhood known for its lively nightlife. One neighbour said a man and woman who fitted the description of Brückner and his girlfriend had lived in a bottom floor flat on Liepmannstraße.

While admitting that she did not know them personally, she said “there was something strange about them, they didn’t fit in.”

Locals said that he was a regular at Club Havana, a bar where he was known as “the workman” due to the fact he often smelt of diesel and was known to spend his free time repairing engines.

He also stood out in the local nightlife due to the fact that he would bring his two dogs – a dachshund named Frau Muller and a rottweiler named Charlie – with him wherever he went.