Up to 100 cows had been culled at a farm within the 3km protection zone and Benn said Debbie Reynolds, the chief veterinary officer, would later confirm that tests done overnight would show the animals had FMD.
He claimed the speed with which the second outbreak was spotted showed protective measures were working to control the disease.
Vets first spotted signs of FMD in the animals on Monday. The second outbreak was on a farm close to Wolford farm, near Guildford, the site of the first infection. Farmers are being urged to examine their stock closely.
The news came as a blow to the farming community who were beginning to hope the disease had been contained. However NFU president Peter Kendall said while the second case was bad news, it was not completely unexpected.
Investigations are continuing into the source of the outbreak, with attention centred on laboratories in the village of Pirbright, and findings are expected soon.
Reynolds has said it was possible recent floods may have contributed to an accidental release of the virus from one of the labs.
At present, she said no decision had been made on vaccines for livestock, but the government has ordered 300,000 doses from private firm Merial, ironically one of the two labs suspected to be at the heart of the outbreak.
Meanwhile the ban of all livestock movements will continue to hit the farming and meat industry hard. The NFU estimates losses of tens of millions of pounds throughout the supply chain.
Defra has set up a helpline in response to the latest outbreak on 08459 335577.