LONDON - British singer and former "X Factor" judge Tulisa Contostavlos, who last week won a legal victory over a tabloid sting story, has been fined for assaulting a celebrity blogger at a music festival.

The 26-year-old celebrity was convicted Friday of hitting Savvas Morgan at the V Festival in August 2013. She had denied the charge.

A judge at Stratford Magistrates Court in London ordered her to pay a 200 pound ($340) fine plus almost 3,000 pounds ($5,100) in other costs.

Last week Contostavlos was cleared of a drug charge stemming from a sting by the Sun on Sunday tabloid.

The newspaper said she had offered to supply drugs to undercover journalist Mazher Mahmood, nicknamed the "Fake Sheik."

A judge halted the trial, saying Mahmood likely lied under oath.