So callous

Three of the creatures, together worth thousands of pounds, were pregnant and one had been on the verge of giving birth to 30 babies.

John Warwick, from Swindon and District Animal Haven, was called out by police to try to identify what was thought to be one snake in a bag that had been dragged out of the lake in Brindley Close by an angler.

But when he got there on Wednesday afternoon he found two more bags were on the bank and yet another had been found floating on the water.

A stunned Mr Warwick said: "The contents were obviously dead and had been so for a few days.

"You can imagine our shock when we discovered not just one tragedy, but 10. To make it even worse when we got the bodies out we found five of the snakes had their jaws locked on to the bags. This clearly indicates they were alive when they were thrown in.

"We also found pebbles which had been used to weight the bags down. It was clearly a pre-meditated and callous way to kill them," he said.

"I have never come across anything like this before. It is just a really wicked and cruel thing to do."

He said he believed whoever the snakes belonged to must have known a lot about keeping them.

One pregnant red blood python, which he valued at around £1,000, was a difficult snake to breed.

Another, a false water cobra worth about £400, would need a lot of equipment and knowledge to breed.

"I would have thought that these animals came from an experienced breeder and quite possible someone well-known in the snake-keeping world."

Mr Warwick appealed for anyone who could help track down the person who threw them in the lake.

"This is a sick way to kill a snake and so totally unnecessary. All animals need protection from people who cause such suffering and these could easily have been re-homed."

Swindon police spokeswoman Alvina Kumar backed his call. "This is without doubt a cruel and deliberate act and we appeal to anyone who can help to track down those responsible to get in touch."