Scotland's leading forensic scientist has developed a pioneering technique to unmask paedophiles who conceal their identity in photographs showing them abusing children.

Until now, detectives have often struggled to identify child abusers and their victims, who are usually photographed from the neck down.

Sue Black, professor of forensic anthropology at Dundee University, has developed a technique that can match suspects with the pictures by looking at the unique features of their hands, such as the pattern of veins, wrinkles and blemishes and the shape of fingers and nails.

The method has already been used to bring two paedophiles to justice and Black has offered to share it with police investigating alleged abuse at a Plymouth nursery.

The science, developed by Black over the past five years, was used recently to identify Neil Strachan, 41, the ringleader of a Scottish paedophile network with links stretching to Australia and America.

The former secretary of Edinburgh’s Celtic East Boys Club was arrested after he took his computer to be repaired and a technician found a picture of a child being abused.

Police later recovered 7,000 images, including one showing the abuser’s hand, which was matched to Strachan’s because of a defect on his thumbnail. He is awaiting sentence. Six gang members were sent to prison last week for a total of more than 40 years.

The new science was also used to identify Dean Hardy, 50, who went to Thailand to abuse children. He confessed when presented with Black’s findings and was sentenced to six years in jail.

Black believes the method could be used by police investigating alleged abuse at Little Ted’s nursery in Plymouth. Vanessa George, 39, a staff member, has been charged with seven offences, including possessing and distributing indecent pictures of children.

“We’re not at all symmetrical,” said Black. “If you look at the pattern of veins on your right hand and compare it with your left, they are completely different. It’s the same for skin blemishes and creases on a knuckle. What we can’t tell yet is what the likelihood is of anybody else having the same pattern. This is very much pioneering science.”

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