A retired detective claims to have uncovered significant evidence linking serial child killer Robert Black with the disappearance of a British toddler who vanished in Germany 35 years ago.

Katrice Lee was snatched from a supermarket while out shopping with her mother and aunt in Paderborn, in the north east of the country, in November 1981.

She has never been seen since, with police convinced she was either drowned in a nearby river or taken by a childless couple.

But those findings do not tally with child abduction expert Chris Clark, who has been ruthlessly studying the crime over the last four years.

The former detective believes that for the first time young Katrice's disappearance can be linked to one of Britain's most ruthless child murderers, Robert Black.

A retired detective claims to have uncovered significant evidence linking serial child killer Robert Black (left) with the disappearance of British toddler Katrice Lee (right) who vanished in Germany 35 years ago

Clark is adamant that the swiftness and subtlety of the way the toddler vanished bears all the hallmarks of Black's killing spree.

But as well as that, he has now found evidence that the Scotland based poster worker was in the Paderborn area at the time of Katrice's kidnapping.

He claims petrol receipts in Black's as yet unreleased police file show he had travelled to the outskirts of the German city to plaster up posters in the lead up to advent, 1981.

Speaking to The Mirror, Mr Clark said: 'Katrice disappeared just a few weeks before Christmas, when Black would have been travelling to Germany to put posters out for alcohol and cigarette firms.

'He'd have been visiting British Army camps along the Rhine, including Paderborn. I'm quite convinced Black quietly befriended Katrice Lee, took her to his van outside the NAAFI and took her away.'

The historical German city lies just off the delivery route Black would have used visiting the country - Highway 33.

Katrice disappeared from a supermarket aisle in Paderborn - where her family were stationed through her soldier father Richard's role with the British Army - on her second birthday.

She was with her mother Sharon and aunt Wendy buying party supplies when she vanished. Both women had taken their eye off her for mere seconds when she was snatched.

Clark, 70, added: 'This was a child abduction by a paedophile and the manner in which she disappeared was exactly the way Black had been able to make children vanish.'

Black (pictured, left) worked as a delivery driver and cruised the length of the UK looking for victims to abduct in the 1970s and 1980s. His reign of terror ended in 1990 when he was caught by police with a barely alive six-year-old girl

Katrice's father Richard Lee (pictured with a photograph of his daughter) said of the link: 'It is a new avenue which is well worth looking into'

Black was serving 12 life sentences for murdering four girls in the 1980s when he died of natural causes in prison in Northern Ireland earlier this year.

The 68-year-old was strongly suspected of killing another 13 children. If involved in Katrice's abduction, it would bring his potential murder spree up to 14.

Black worked as a delivery driver and cruised the length of the UK looking for victims to abduct in the 1970s and 1980s.

His reign of terror ended in 1990 when he was caught by police with a barely alive six-year-old girl.

Katrice disappeared from a supermarket aisle in Paderborn while shopping with her mother Sharon (pictured) and aunt Wendy on her second birthday

She was found hooded, bound, gagged and stuffed in a sleeping bag in the back of his van in the Scottish village of Stow.

In 1994 he was found guilty of the murders of Susan Maxwell, 11, Caroline Hogg, five, and Sarah Harper, ten. Black was also found guilty in 2011 of abducting Jennifer Cardy, nine, in his van as she cycled to a friend’s house in 1981.

He sexually abused and killed her before dumping her body in a nearby beauty spot.

Only Moors Murderers Ian Brady and Myra Hindley – whose five victims were aged ten to 17 – killed more children in modern British criminal history.

Black's file is held by Devon and Cornwall Police, who were set to charge him with the murder of Genette Tate, 13, before he died of a heart attack in January.

The serial killer is also considered the prime suspect in 10-year-old Silke Garben's brutal murder. The schoolgirl vanished from near her home in Detmold, 20 miles outside of Paderborn, in 1985.

Her lifeless body was discovered dumped on a roadside weeks later. She had been strangled.

Mr Clark believes the disappearance of another girl, Ramona Herling, 11, was also in the Black mould. She was taken just 14 miles from where Katrice was last seen eight years earlier.

Katrice's father Richard said of the link: 'It is a new avenue which is well worth looking into.

A Ministry of Defence spokesman added: 'The Royal Military Police are following a number of lines of inquiry and it would be inappropriate to comment further while these efforts continue.'