Bruno Mars, a former Hawaii child entertainer and rising recording industry star, was arrested on suspicion of cocaine possession in Las Vegas, police said.

Mars, whose real name is Peter Hernandez, was detained in the bathroom of the Hard Rock Hotel & Casino by hotel security at about 2 a.m. Sunday.

Las Vegas police said Hernandez was in possession of 2.6 grams of a white powdery substance believed to be cocaine. He was booked for investigation of cocaine possession and released a few hours later.

An aide to Clark County District Attorney David Roger in Las Vegas said the case was under review and that formal charges had not been filed. Hernandez was given a court return date of Nov. 18.

Mars, 24, is known for singing and for co-writing the hits "Nothin’ on You" by B.o.B and "Billionaire" by Travie McCoy. He also co-wrote "Right Round" by Flo Rida. Earlier this month, the record label Elektra announced his tune "Just the Way You Are" was the most downloaded song on iTunes.

He performed a medley of songs on MTV’s Video Music Awards earlier this month with B.o.B and Hayley Williams of Paramore.

Mars, a Roosevelt High School graduate, performed in many local venues as a youth, starting as an Elvis impersonator at age 4. As a teenager he performed as Michael Jackson at the Waikiki Beachcomber Hotel. Mars moved to Los Angeles in 2002 to pursue his entertainment career.

Hernandez’s publicist at Atlantic Records did not immediately return messages from The Associated Press seeking comment. A hotel spokeswoman declined comment. It was not immediately clear whether Hernandez has an attorney.

An arrest report for Hernandez said a bathroom attendant told police Hernandez was taking a long time in a stall with a bag of a white, powdered substance. The attendant alerted a security guard, who confronted Hernandez as he left the stall. The security guard said he asked Hernandez to hand over any narcotics he had and that Hernandez pulled a bag containing white powder from his left-front jeans pocket.

Hernandez was taken to a holding cell, where he was questioned by an arresting officer. When asked what was going on, Hernandez replied, "Can I speak to you honestly, sir?" and said he acted foolishly and had never used drugs before, the arrest report said.

Mars performed a show Saturday night at the Hard Rock’s Wasted Space nightclub. The hotel-casino is separate from the restaurant chain with the same name.

"Just the Way You Are" is No. 3 on the Billboard Hot 100 chart. He sang the hooks in "Nothin’ on You" and "Billionaire" — both chart-toppers — and co-wrote and produced Cee-Lo Green’s latest expletive-laden single. Mars’ debut album, "Doo-Wops & Hooligans," is scheduled for release Oct. 5.