Reality TV star Kristin Cavallari found herself in police custody in Chicago, Illinois on Friday morning (06Sep13) after a mix up over her driver's license.

The former The Hills star, who is married to footballer Jay Cutler, took to her Twitter.com page to reveal all about her legal run-in, suggesting she was busted for not having a valid driver's permit.

In a post online, she wrote, "Who knew having a California driver's license in Illinois was a CRIME to be escorted to the police station to post bail?!! What a morning."

Cavallari has been spending time in the state with her husband, who plays for the Chicago Bears, but she insists she isn't a full-time resident of Illinois: "I still have an apartment in LA so I'm a resident of California."

Drivers in Illinois are required to apply for a new state license after living in the area for 90 days, or face citation.