British TV personality Kelly Osbourne has lashed out a security guard in Australia, calling him a "a first class twat." The 28-year-old daughter of Ozzy and Sharon Osbourne claimed the guard, who was stationed at The Star casino in Sydney, called her a liar and treated like a criminal.

Kelly, who is in Sydney to promote a column that she wrote for local magazine Cleo, was livid after she was allegedly mistreated by a security personnel in the casino.

"In disbelief at how rude the security guard 'Sam' at the Star casino AU was to me & my friends for NO reason he is a first class twat," she wrote the scathing attack Monday night on her Twitter page.

"All I did was show him my ID to get into the casino he called me a liar & treated me like i was a criminal!"

But according to an insider at the casino, she was just not happy about being asked to get additional identification cards before she could enter the premises.

The security apparently told her she had to get her passport because international drivers licenses, which she presented to him, are not accepted on the gaming floor.

"She had to go back to her room and get her passport and she was clearly not happy about it," the insider told Fairfax Media.

A spokeswoman for the casino added to Sydney Morning Herald, "Our security team member asked her for additional ID, as she was only carrying an international drivers license, which is standard procedure. The matter has now been resolved with Ms Osbourne and we are looking forward to hosting her tonight at the Cleo magazine launch party."

The morning after the incident, Kelly appeared to be in a more gracious mood.

She tweeted, "Thank you #StarCasino for being so accommodating & dealing with last nights drama so graciously! I cant wait for the @cleomag party tonight!"

Kelly is the new columnist for the beauty and fashion magazine Cleo, which will have its re-launch tonight.