THIEVES who stole �10,000-worth of fish from a garden pond must have used explosives, an electric shock or drugs to take them, their owner has said.

Henham resident Jonathan Leech spent 25 years developing a “sustainable pond ecosystem” – a fond hobby of his which allowed him to have 26 koi carp.

But after discovering that at least half of them were stolen during an overnight raid between June 26 and 27, the 64-year-old said he is considering replacing his pond and giving the remaining fish away.

“The fish must have been stunned using anaesthetic, electric shock or least likely explosives, because the pond is 7ft deep and you would never be able to get them out any other way.

“I think using some sort of anaesthetic is the most likely because the thieves could easily have parked in a layby, waited for it to take effect and then returned when the fish were docile and had floated to the top.”

He said it was unclear exactly how many of the fish – some of which had grown as big as two-and-a-half feet long – had been taken because of the raised pond’s depth.

“I’ve seen a couple that have turned pink – which is what happens when they get stressed,” he told the Reporter. “Now I’ll probably have to close the pond down and give the remaining carp away because they need to be in a balanced ecosystem.”

The engineer has also issued a warning to other pond owners to be mindful of the threat posed by criminals – encouraging those vulnerable to take steps to increase their security.

“I don’t think I’ll get my fish back but if I can help raise awareness of this type of incident to stop it happening to someone else then at least that’s something,” he added.

Police have appealed for anyone with information to call 101.