By RUPERT CORNWELL in Washington

They could smell a hotdog a kilometre away.

But Russell Lee Ebersole's dogs were a dud at the task for which the United States Government paid him more than US$700,000 ($1.2 million) - sniffing out explosives and protecting America from acts of terrorism.

Ebersole's career as purveyor of dodgy canine security ended on Saturday, when he was convicted by a Virginia court on 25 counts of fraud and two counts of making false claims to the federal Government.

He faces up to eight years in prison and a fine of US$1.4 million ($2.4 million) when he is sentenced on September 5.

The verdicts ended an operation set up to cash in on increased security awareness since the September 11, 2001, terror attacks. Ebersole's marketing materials included prizes and trophies won by others.

He faked records to produce proficiency certificates for such dogs as Rocky, Sho Shien and Woody, and wildly exaggerated the amount of training they had received.

The plot was exposed when investigators put the animals through their paces.

Federal prosecutor Thomas McQuillan said the dogs "didn't so much as sneeze" when, in a test, federal officials drove past them and into the parking lot of the Federal Reserve in three vehicles loaded with 22kg of TNT, 22kg of dynamite and 7kg of plastic explosives.

In another trial, the dogs were oblivious to marijuana they were supposed to detect. Instead, they strained at the leash towards a hot dog stand.

McQuillan described Ebersole's behaviour as "obscene", accusing him of "seeking to profit from a great national tragedy". Ebersole plans to appeal.