Farmers across the UK are on high alert as Defra investigates a second possible case of foot and mouth disease in Surrey.

Defra said that as part of surveillance activity within the 3km zone set up around the site of the outbreak discovered last Friday at a farm in Pirbright, near Guildford, Surrey, a further herd of cattle with clinical signs of foot and mouth disease had been found. Results are expected later.

Meanwhile, the Meat and Livestock Commission has warned that the foot and mouth outbreak, the first since 2001, could cost the industry more than £10m a week.

The National Beef Association has also warned the latest outbreak could lead to a price crash. "What we are concerned about is a complete and utter price crash when farmers desperately need to get as much money from the market as possible," director Kim Haywood told the Daily Telegraph.

Anthony Gibson from the National Farmers' Union added: "The longer this goes on and the more cases we get, the greater the costs are going to be. We know from bitter experience that a ban on exports leads to very low prices."