BEVERLY HILLS, Calif. (AP) – Lindsay Lohan was arrested on suspicion of driving under the influence Saturday after her convertible struck a curb, and investigators found what they believe is cocaine at the scene, police said.

Ms. Lohan, 20, and two other people were in her 2005 Mercedes SL-65 when it crashed on Sunset Boulevard around 5:30 a.m., Sergeant Mike Foxen said. It appeared the actress was speeding, Lieutenant Mitch McCann said at an afternoon news conference.

Officers at the scene found a “usable amount” of a drug tentatively identified as cocaine, Lieutenant McCann said. He declined to say where the drug was found other than to say Ms. Lohan was not carrying it.

Ms. Lohan, who spent time at a rehabilitation center earlier this year, was driven in another car to a hospital for treatment of minor injuries, Lieutenant McCann said. The two other people in her car were not hurt.

Officers received a 911 call about the accident and arrested Ms. Lohan at the hospital for investigation of misdemeanor driving under the influence of alcohol or drugs, Lieutenant McCann said.

She was released from custody because she was admitted to the hospital, police said.

Lieutenant McCann declined to comment on Ms. Lohan’s blood-alcohol level. He said the case will be presented to the District Attorney’s Office where the actress could face more charges, including felonies. Her tentative arraignment date is Aug. 24.

The crash was Lohan’s third accident in about two years. In October 2005, Ms. Lohan and a passenger received minor injuries when her convertible hit a van in West Hollywood. Authorities said the van driver, who also received minor injuries, was at fault.

Months earlier, Ms. Lohan collided with a minivan when she made a U-turn as the van, carrying paparazzi, followed her from a Los Angeles restaurant. A photographer was arrested for investigation of assault with a deadly weapon but prosecutors declined to charge him.

That crash was credited with prompting Gov. Arnold Schwarzenegger to sign a law that set steep financial penalties for paparazzi who commit assaults while trying to obtain celebrity photos.

Ms. Lohan publicist Leslie Sloane Zelnik did not immediately return an e-mail requesting comment.

Ms. Lohan said in January that she had checked into a rehabilitation center for substance abuse treatment. Her publicist confirmed in December that the actress was attending Alcoholics Anonymous meetings.

Ms. Lohan told Allure magazine during an interview for its May issue that she decided to enter the secluded Wonderland Center at the suggestion of her therapist.

“It’s so weird that I went to rehab. I always said I would die before I went to rehab,” Ms. Lohan told the publication.

Ms. Lohan’s latest movie, “Georgia Rule,” is in theaters now. The actress’ other screen credits include “Mean Girls,” “Bobby,” “A Prairie Home Companion” and “Freaky Friday.”