LAS VEGAS — Paris Hilton was arrested late Friday after a police motorcycle officer smelled marijuana smoke wafting from a black Cadillac Escalade driven by her boyfriend on the Las Vegas Strip, then found cocaine in her purse, authorities said.

A crowd quickly gathered when Hilton and Las Vegas nightclub mogul Cy Waits were stopped about 11:30 p.m. Friday in the vehicle near the Wynn Las Vegas resort, police said.

The 29-year-old celebrity socialite was taken into the hotel “to keep her safe” during the initial investigation, police Lt. Wayne Holman said.

Police Officer Marcus Martin said the motorcycle officer pulled the Escalade over on Las Vegas Boulevard after noticing smoke that smelled like marijuana. Police later found a substance in Hilton’s purse that tests showed to be cocaine, Martin said. He didn’t say how much of the drug was found.

Hilton was arrested on suspicion of felony cocaine possession.

Waits, 34, was arrested on misdemeanor suspicion of driving under the influence of alcohol or drugs.

Both were booked into the Clark County jail, where Martin said Hilton was released without bail about 2:45 a.m. Saturday.

Less than an hour later, Hilton’s Twitter account was updated with a posting that said the actress was in bed watching the television show “Family Guy,” and then that she was going to sleep. It was unclear if the tweets came from her, were posted by time-release or were sent by someone else.

If convicted of the low-grade felony, Hilton would get probation. Any violation of probation would be punishable by one to four years in Nevada state prison.

Clark County District Attorney David Roger declined comment Saturday about the case.

Hilton’s attorney, David Chesnoff, told The Associated Press on Saturday morning that he was still gathering facts about the arrest.

“I caution people not to rush to judgment,” he said.

Waits’ lawyer, Richard Schonfeld, said Waits posted $2,000 bail and was expected to be released Saturday.

Court appearance dates for Hilton and Waits were not immediately available.

Schonfeld said he was “troubled by the circumstances” leading to the arrest, but declined to specify his concerns.

“As the case proceeds, a lot of facts are going to come to light that will ultimately lead to exoneration,” Schonfeld said.

Hilton’s manager did not immediately respond early today to telephone calls for comment. Hilton’s publicist, Dawn Miller, did not immediately return an e-mail message.

A spokeswoman for Wynn Resorts in Las Vegas did not immediately respond to messages seeking comment.

Waits and his twin brother, Jesse, are managing partners of the Tryst Nightclub inside Wynn Las Vegas, Drai’s after hours club at Bill’s Gamblin’ Hall & Saloon, and XS The Nightclub at Wynn’s Encore resort. A spokeswoman for Harrah’s resorts declined immediate comment.

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