The two-foot-long marble shark (60 centimetres) was stolen on Saturday from Peter Newman's garden in Farnborough, southwest of London.

Newman, 68, kept the female mottled brown fish in an aquarium in a brick shed. It is one half of the only breeding pair of marble sharks in Britain.

The animal is worth around 2,500 pounds.

Newman found the shed door open and all the lights on inside, then realised his prize shark was missing.

He and his wife June run an aquatics shop from their home and fear that customers who came to see the baby sharks have eyed up the mother and returned to steal her.

June Newman said the shark thief or thieves would have needed a ladder to get up to the tank.

"It's very upsetting for us as the babies have lost their mother and we cannot breed any more," she said.

"They are rare in this country. As far as we know, we are the only people here to breed them."

Police constable Stephen Court said it may have been a targeted burglary.

"The victim is desperate for the fish to be returned and we urge anyone with information about the burglary to contact us," he said.

"Due to the unusual type of shark, it will be difficult to sell in this country."

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