Britney Spears has reportedly taken a turn for the worse during a magazine shoot for OK! magazine in the US.

The singer was said to have treated a designer dress like "a napkin" by wiping grease on it and also allowed her puppy to poop on a $6,700 (£3,274) designer gown, the magazine said.

Rob Shuter, Entertainment Director of OK! Magazine, said: "We really were looking forward to seeing Britney and sitting down with her and unfortunately what transpired was shocking and sad.

"Britney left the shoot with about twenty thousand dollars worth of clothing that OK! Had borrowed from some of the biggest designers in the world for the shoot.

"And then in addition there was about five thousand dollars worth of stuff that had been damaged including the dress that her dog had relieved himself on."

OK! publicist Brian Strong said the magazine would not publish photos of Spears from the shoot due to legal reasons, and added they would provide "a very real account" of its interview with the singer.

Representatives for the 25-year-old are yet to comment.