A FISHERY owner in Worcester was in for a shock when he discovered giant caviar-producing sturgeon from Eastern Europe swimming around in one of his pools.

The bemused proprietor was so alarmed by the discovery of the massive fish, which are 90cm (36ins) long and are not native to British waters, that he called in the experts at the Environment Agency (EA).

Officials from the Government body attended the fishery, which does not wish to be identified, and removed two of the sterlets. These are small sturgeon and are considered a delicacy in Russia - producing some of the world's finest caviar.

Oliver Blackburn, Midlands spokesman for the EA, said: "We were called in by the fishery owner when he discovered that the fish were in the pool when he was draining it.

"There is still no indication at this stage as to how they got there."

He said that the threatened species had to be removed from the pool because it was connected to a brook leading to the River Severn.

"Sterlets are a non-native species and therefore must not get into a wider river environment," he explained.

The EA's Fisheries Officer Andy Roberts said that he feared the finding could spark the discovery of yet more sterlets infesting our waters, threatening other fish.

He said a team of officers was now set to carry out searches and investigations across the River Severn, downstream of the Worcester fishery, to ensure there are no sterlets living in the area.

"This is the first time we have come across these fish in Worcestershire," he said.

"Although interesting, it represents an unfortunate situation where there has been a recent increase of these alien species being found.

"These fish pose a real threat to the environment and their removal is part of our work to protect the rivers of England and Wales.

Once they were caught at the Worcester fishery, the sterlets were taken to the EA's fisheries laboratory in Brampton, where new homes will be found for them.

They are likely to be stocked in fisheries which are not connected to a river once the go-ahead has been given by EA and Defra officials.