An Apple iPhone advert has been banned by the advertising standards watchdog for exaggerating the phone's speed.

The advert compared the iPhone's 3G and 2G models

The advert boasted the new 3G model was "really fast" and showed it loading internet pages in under a second.

The Advertising Standards Authority (ASA) upheld complaints by 17 people who said the TV advert had misled them as to its speed.

Apple UK said it was comparing the 3G model with its 2G predecessor and its claims were "relative not absolute".

The advert repeatedly stated that the phone was "really fast" and showed news pages and the Google maps service taking just fractions of a second to appear.

Text on the screen said: "Network performance will vary by location."

After upholding the viewers' complaints, the ASA said the advert must not appear again in the same form.

It said the advert was likely to lead viewers to believe that the device actually operated at or near to the speeds shown in the advert.

The watchdog concluded: "Because we understood that it did not, we concluded that the ad was likely to mislead."

Apple said its claims were "relative rather than absolute in nature" - implying the 3G iPhone was "really fast" in comparison to the previous generation - and therefore the advert was not misleading.

The company also said the average consumer would realise the phone's performance would vary - a point they said was made clear by the text stating "network performance will vary by location".