Market analysts believe that the millionaire financier has accumulated roughly a 10% share in the AIM-listed company via contracts for difference - instruments that effectively allow investors to bet on a company's share performance.

Neteller is currently valued at over £166m, but its stock has plunged during the year by more than 80%, largely due to a clampdown on internet betting by the US government. In January, it was valued at over £1bn.

Some analysts believe that Desmond may buy the company to merge it with his successful Betdaq operation, an online betting exchange.

Neteller's clients include betting chain Victor Chandler. Three weeks ago Neteller said that its third quarter profit rose 31% to almost $30m after tax, while revenue climbed 48% to $66.7m. It said it had almost 3.2m customers, and is signing up an average of over 3,200 people a day in the past quarter. It added that year-todate revenue was $185.6m at the end of October, up 57 % from $118.4m for the same period in 2005.