Financial spam emails are being used to boost share prices, according to research from an internet security company.

While most spam is designed to sell medical products or gather email addresses, other messages are targeted at people dabbling in the stock market, containing what claims to be a 'hot tip' for the stock exchange.

Panda Labs found that the share price of one of the companies mentioned in a series of spam emails rose over a period of several days. The price even increased by 12 per cent in one day.

Luis Corrons, director of Panda Labs, said: "This new use of spam would seem to be quite effective from what we have seen so far. There are two possible sources: either the companies themselves are trying to boost their stock value, or individuals that have bought cheap stocks are looking for a quick profit on selling them."