Madeleine McCann suspect Christian Brueckner kept kids' clothes and swimwear in his mobile home

WARNING: Graphic content.

Girls swimmers and kids clothing have been found in the old campervan of the prime Madeleine McCann suspect.

Convicted paedophile Christian Brueckner bought the red and white Allegro Bay RV in early 2010 – three years after moving back to his native Germany from Portugal.

Friends of the 43-year-old convicted sex offender said he used it to drive regularly back and forth between Germany, Spain and Portugal and once boasted how he could "carry children and drugs" inside.

Now, police have found clothes and swimwear belonging to young girls inside after seizing the campervan as part of their probe into missing Inga Gehricke, a five-year-old Gerrman girl who disappeared in 2015 during a picnic with her parents, The Sun reports.

Brueckner, was also recently named by police as the prime suspect in the girl's disappearance.

According to the report, Brueckner used a derelict crate factory in the small town of Neuwegers­leben, an hour outside of Berlin, as a weekend pad where he kept the RV.

The items were found there in 2016 along with USB sticks containing images of child sex abuse.

Other images on the sticks included some of Brueckner partially naked or wearing stockings performing a solo sex act, as well as others the British press deemed "too graphic" to describe.

The six data sticks and two memory cards were found buried under the body of his dog at the factory, wrapped in a plastic bag.

'BIZARRE BEHAVIOUR'

The revelations came in a documentary broadcast by Spiegel TV which included an interview with a friend, identified only as Bjorn R, who revealed Brueckner's bizarre behaviour while he lived in Portugal – a stint that ran over the 2007 period little Maddie disappeared.

"Alcohol sometimes loosened his tongue. He said that he was in Portugal and he got in everywhere and stole cameras," he 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."

Last week, a former ambulance driver who met Brueckner and saw the RV said: "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'."

While living in Braunschweig, Brueckner ran a kiosk between 2013 and 2015 and he was pictured inside wearing dark sunglasses.

Bjorn told the documentary his former friend had been contacted in 2013 by police investigating Madeleine's disappearance.

He said: "One day I came into the kiosk and he was a little bit distraught and said, 'Hey, look what I've got here' – and he showed me a subpoena for the Madeleine McCann case.

"You could see it churned him up a bit but he wasn't panicking and he wasn't saying, 'They are on my heels'.

"I think he said he had been there but that he had nothing to do with it and that was that."

Brueckner was named prime suspect over the 2007 disappearance of three-year-old Madeleine earlier this month by German cops.

Madeleine vanished from an apartment in Praia da Luz on Portugal's Algarve coast while on holiday with parents Kate and Gerry.

Two years earlier, Brueckner had raped a 72-year-old American tourist in a nearby villa and was later sentenced to seven years.

He is currently serving time on this charge and on a drugs rap.

He also has 17 convictions across Europe including for sex offences against children.

It was recently reported Maddie's parents, Kate and Gerry, had received a letter from German police confirming their daughter is dead.

But in a statement posted online, Kate and Gerry denied the existence of any such letter.

"The widely reported news that we have a received a letter from the German authorities that states there is evidence or proof that Madeleine is dead is false," they said.

"Like many unsubstantiated stories in the media, this has caused unnecessary anxiety to friends and family and once again disrupted our lives," they added.