Burger King's Twitter feed has fallen victim to hackers who changed its branding to that of rival fast food chain McDonald's on the social networking site.

No one has admitted being behind the stunt, but hacking collective Anonymous appeared to have tweeted about the incident extensively.

The Burger King account was suspended on Monday night but a screengrab posted by AnonymousPress showed the BurgerKing's Twitter page where it was written: "Burger King USA official Twitter account. Just got sold to McDonalds because the whopper flopped."

Posts from the Burger King account earlier in the day also contained racial slurs, references to drug use and obscenities.