Britain’s advertising watchdog, the Advertising Standards Agency, is preparing to launch a review into how internet services are being advertised.

Adverts by broadband providers can be seen claiming to provide unlimited services, but these ‘unlimited’ broadband packages often have a usage limit or fair usage policy hidden in the small print, which contradicts the 'unlimited' claim of the service.

Meanwhile, the ASA has ordered Vodafone to stop using its one of its adverts for its Sure Signal femtocell device, saying it misled customers.

The advert, which showed a man leaning out of a window to get reception on his mobile phone, for the 3G booster device attracted complaints from rival network providers as well as some consumers.

Vodafone’s concerned advert was claiming that "Only Vodafone can guarantee mobile signal in your home".

Vodafone’s femtocell device claims to give better indoor coverage of 3G mobile phone signals, which prove sometimes problematic to receive when inside the office or home.

But, the watchdog said claims made by the advert were misleading as Vodafone did not control the availability and performance of the broadband connection. In addition, Vodafone did not make it clear that consumers would need broadband connections with speeds of 1Mbps to operate the service.