Celebrity endorsements on social media sites are being watched by the Office of Fair Trading.

Parcel delivery and courier services paying celebrities to endorse products on Twitter and blogs are facing a new clampdown.

The Office of Fair Trading (OFT) has clarified its stance on blogs and social media, saying that online marketing practices that do not disclose they include paid-for promotions will classed as deceptive.

In a statement, the OFT said: "This includes comments about services and products on website blogs and microblogs such as Twitter.

"Online promotional activity, just like any promotional activity, must clearly identify when promotions and editorial comment have been paid for, so consumers are not misled."

Celebrities have an immense amount of influence on social media sites, which is one of the reasons that concerns have been raised.

A study by Klout showed that Canadian pop sensation Justin Bieber has more influence on sites like Twitter and Facebook than both the Dalai Lama and the US president.

Posted by Laura Rathbone

Article Added: 12/01/2011 09:45:35