Paris Hilton is shown in a police booking photo released Saturday by Las Vegas police. (Las Vegas Metropolitan Police Department/Associated Press)

Paris Hilton denied owning the purse in which police allege less than a gram of cocaine was found after a traffic stop on the Las Vegas Strip, according to an arrest report released Monday.

"She told me the purse was not hers, that she had borrowed it from a friend," Las Vegas police Lt. Dennis Flynn wrote in his report of Hilton's arrest shortly before midnight Friday. The friend was not identified.

The 29-year-old celebrity socialite acknowledged owning $1,300 US in cash, several credit cards, a package of Zig-Zag rolling papers and a broken tablet of the prescription asthma medication Albuterol also found in the purse late Friday during her arrest at the Wynn Las Vegas resort.

Hilton was arrested after her boyfriend, 34-year-old Las Vegas nightclub mogul Cy Waits, failed field sobriety tests given by a motorcycle officer.

She faces a low-grade felony possession of cocaine charge that could get her probation if convicted.

Flynn said a small plastic "bindle" containing 0.8 grams of cocaine powder fell out when Hilton opened the purse to get a tube of lip balm. She denied owning it.

"Hilton admitted the Albuterol ... was hers and is prescribed to her, but the suspected cocaine was not," Flynn wrote. "I asked Hilton whose cocaine it was, and she said she had not seen it but now thought it was gum."

Hilton's lawyer, David Chesnoff, said Monday that he would not comment on the police report.

"As previously stated, the facts of the situation will be tested in a courtroom," he said. Hilton was freed without bail before dawn Saturday after spending less than three hours handcuffed on a booking room bench at the Clark County jail.

Waits, 34, spent the night in jail before he was released on $2,000 bail. He faces a misdemeanour charge of driving under the influence of alcohol or drugs. Flynn said that while Hilton was in the Escalade, she told him she was "extremely embarrassed, due to all the people taking pictures of her."

Flynn estimated the crowd at about 100 people, many of whom used cellphone cameras to snap photos.