A THEORY that a two-year-old girl who disappeared 35 years ago was murdered by child killer Robert Black has been discounted by her father.

Richard Lee from Hartlepool, whose daughter Katrice disappeared from a Naafi shop in Germany in 1981, said that line of inquiry had already been checked out, and found to be a red herring.

He criticised retired detective Chris Clark, 70, who has been researching Black's crimes for the past four years, for "using my family's tragedy" to promote his forthcoming book.

Mr Clark has promoted a theory that the killer abducted Katrice Lee from Paderborn, Germany, and said the way she disappeared without trace matched Black's methods.

And he said he believed Black's petrol receipts in a file not released yet by police would prove Black was in the area at the time.

But Mr Lee said: "That line of inquiry has already been checked out and Black was not in the area.

"As a family we are not naive, and I have said this, we know there could be a dark side to Katrice's disappearance.

"But the fact is that it's all been checked, and it couldn't have been Black.

"I have had my daughter Natasha on in tears about this - it has really upset her."

Black, who died earlier this year aged 68, was serving 12 life sentences for raping and murdering four young girls in the 1980s.

Katrice disappeared on her second birthday, while her mother Sharon, and aunt, turned their backs for a second in the busy supermarket, close to the Schloss Neuhaus British Army base, to pick out some crisps for her party.

There were three theories - that she was kidnapped and murdered, that she drowned in a nearby river, or that she was stolen to order for a childless couple.

Mr Lee, who was a serving British soldier when Katrice disappeared, said he believes she is still alive.

"She will be 36 now," he said.

"I believe we will find her. Hope is what sustains us."