In what could begin a new era for forensic science, the police in Britain have arrested a drug dealer based on fingerprints they found on a WhatsApp image sent by the criminal to his clients.

The photograph showed part of the dealer's hand "and there was potentially a fingerprint," the BBC reported late on Sunday.

The scientific support unit scanned the image into its system but could not find a match because the photograph contained just parts of the middle and bottom of a finger visible while records only keep the top part.

However, other evidence was enough for the police to guess who was behind the drugs operation.

"While the scale and quality of the photograph proved a challenge, the small bits were enough to prove he was the dealer," Dave Thomas from South Wales Police's scientific support unit was quoted as saying.

Police arrested a man on a tip-off that said drugs were being sold in Wales. While checking his phone, they found an image of the drug dealer named Elliott Morris holding ecstasy tablets in his palm.

"There was the photograph of the hand holding pills that seemed like it was sent to potential customers saying 'these are my wares, I'm selling these'," Thomas said.

"It has now opened the floodgates and when there is part of a hand on a photograph, officers are sending them in," he added.

According to the police officer, the dealers are using the technology not to get caught and the police need to keep up with advancements.