Spammers have pounced on rising petrol prices in the US by offering bogus fuel discounts.

The spam directs the user to a link which claims to offer a 70 cent discount on each gallon of petrol. The spam originates from a sender using the alias 'Gas Saver'.

Researchers say that the new format is somewhat unusual. Spam emails are usually devoted to financial scams, malware propagation or products such as pharmaceuticals.

Security firm McAfee said that the fuel discount spam currently accounts for less than 0.2 per cent of all spam, but that this could escalate if fuel prices continue to rise over the summer.

"Given the high price of oil it is not surprising that a spammer has started selling a product which claims to reduce gas bills," said McAfee researcher Jeremy Gilliat.