Since Madeleine vanished on a family holiday in the Algarve nearly two decades ago, leads have been scarce. The investigation delves into alarming items found at the disused factory once used by Brueckner, alongside his sickening fascination with little ones. The programme ‘Madeleine McCann: Inside the Secret Evidence’ delves into the unsettling details of children’s swimming costumes and toys uncovered on his premises.

According to The Sun’s documentary, police also stumbled upon a sinister mask, firearms, and depraved fictional tales of child abduction authored by Brueckner.

He wrote: “A very small girl enters the room. She’s definitely not older than five. Blonde, long hair tied in pigtails bounces cheekily back and forth as she comes towards me. I feel like I’m in paradise right now.”

Additionally, one grim story allegedly crafted by Brueckner narrates applying chemical ether to a mother and toddler outside a nursery. The documentary also sheds light on an 80gb hard drive that could have been pivotal in convincing detectives to pursue Brueckner.

The hard drive placed Brueckner at the centre of the search location in Arades Dam, Portugal. The documentary also chillingly revealed that Brueckner expressed a desire to “capture something small and use it for days.”

He ominously suggested that it wouldn’t matter if “evidence is destroyed afterwards” before adding: “I’ll make a lot of films…hehe.”

Police files indicate this was a significant breakthrough in understanding the case since German police named Brueckner as the prime suspect in the Madeleine McCann case in 2020.

The documentary also highlighted Brueckner’s refusal to cooperate with police questioning or provide an alibi. To date, Brueckner has not been formally charged in connection with Madeleine’s disappearance or murder.

The programme also featured an interview with Hazel Behan, 41, an Irish holiday representative who Brueckner was acquitted of raping in 2005 during a trial in Germany last year. The documentary shed light on investigators’ concerns that Brueckner might take what he knows to his grave, leaving no closure.

The most recent search for clues related to Madeleine McCann’s disappearance took place over three days last week in Praia da Luz, close to where Brueckner is known to have camped.

German investigators, assisted by Portuguese police, were seen using diggers and radar to probe the ground. However, despite their efforts, they found “nothing of consequence.”