The X Factor has been cleared of breaching product placement rules by British watchdog Ofcom.

An investigation had been launched into the latest run of the ITV show, which saw Rak-Su crowned winners, following complaints about references to the Three mobile phone network.

The UK regulator looked into whether the show broke rules in an episode featuring judges' houses.

Since early 2011, TV programmes made for British audiences have been able to contain product placement as long as references are not unduly prominent.

Sharon Osbourne

The phone was featured when Sharon Osbourne sent one of her contestants a text and when fellow X Factor judge Louis Walsh told singers they would be heading to Osbourne's house.

A contestant was also given a branded phone to call home after discovering that they had got through to the next stage of the competition.

An Ofcom spokeswoman said: "We carefully considered references to a mobile phone network on The X Factor.

"Commercial broadcasters are allowed to include products in their programmes, as long as they don't promote them, give them too much prominence, and viewers are notified.

"We found these references were in keeping with the narrative of the programme, and were brief and few in number."