Paris Hilton in Las Vegas cocaine charge

A crowd quickly gathered near the stop on Las Vegas Boulevard and Hilton was taken into the hotel "to keep her safe" during the initial investigation, Lt Wayne Holman said.

The 29-year-old socialite and Las Vegas nightclub owner Cy Waits were booked into the Clark County jail, police said. Hilton was released early yesterday morning without bail.

Officer Marcus Martin said police found that Hilton had a substance that tests later showed to be cocaine, but he did not say how much of the drug was found. She was arrested on a felony cocaine possession charge. If convicted of the low-grade felony, she would get probation, but any violation would be punishable by one to four years in jail.

Jail records showed that Waits, 34, remained held pending a court appearance on a charge of driving under the influence of alcohol or drugs. Hilton's court date was not immediately available.

Hilton hadn't commented on the arrest publicly, although she appeared to be tweeting.

Earlier this week, a 31-year-old man allegedly tried to break into Hilton's Los Angeles home. Authorities said that someone carrying two big knives banged on her window on Tuesday. She posted a photo of the arrest on Twitter and described it as "scary." Nathan Lee Parada faces a burglary charge.

Hilton was arrested this summer after the Brazil-Netherlands World Cup match in Port Elizabeth, South Africa, on suspicion of possession of marijuana. The case was dropped. In 2007, she pleaded no contest to alcohol-related reckless driving and was sentenced to 45 days in jail.

After her release, she said the experience had caused her to re-evaluate the role partying played in her life. She said she wanted "to help raise money for kids and for breast cancer and multiple sclerosis."

Hilton is most famous for her tabloid exploits and reality TV series The Simple Life. She also appeared in the films Bottoms Up, The Hottie & the Nottie and House of Wax.