Sky has been ordered to withdraw an advert for its Anytime+ television service.
The satellite TV and broadband provider has been rapped by the Advertising Standards Authority (ASA) for claiming customers can enjoy hundreds of movies without paying "one penny more".
Rival service provider Virgin Media complained about the advert, which it claimed had the potential to mislead consumers.
This is because customers are required to subscribe to premium channels Sky Movies 1 and 2 in order to watch films using Anytime+.
"Because the claim immediately followed the reference to hundreds of movies and box sets, viewers would expect to be able to watch films and box sets at no extra cost as part of the Anytime+ service," the ASA said.
Virgin Media has also fallen foul of broadband marketing regulations this year, over its Stop The Broadband Con campaign.
The firm criticised its rivals for exaggerating the download speeds available to consumers, but was found to have committed the same offence.