Anna Nicole Smith, a former Playboy Playmate who gained tabloid attention for her marriage to an 89-year-old oil tycoon, has died after collapsing in a Florida hotel room.

Smith, 39, was staying at the Seminole Hard Rock Hotel and Casino in Hollywood, Fla. Her bodyguard performed emergency CPR before officials rushed her to Memorial Regional Hospital.

"At 2:49 p.m. we were advised by hospital personnel that Anna Nicole Smith had died," Police Chief Charlie Tiger told reporters.

Officials said Smith's death is now under investigation and an autopsy will be conducted on Friday.

The former model had struggled against tragedy and various legal battles in the past few years.

She had a baby girl just five months ago, Danielynn Hope Marshall Stern, which prompted calls for a paternity test from former boyfriend Larry Birkhead.

Smith's personal lawyer, Howard K. Stern, has maintained that he is the girl's father.

And just three days after her daughter's birth, her 20-year-old son Daniel Smith died suddenly in the Bahamas, apparently from a drug overdose.

Smith became Playboy's Playmate of the Year in 1993, and just one year later she married wealthy oil tycoon J. Howard Marshall.

The 89-year-old billionaire had met her at a Houston strip club.

The two soon married but he died about a year later, igniting a lengthy court fight over the tycoon's estate. Smith initially won US$474 million, but that decision was later overturned.

In May, the U.S. Supreme Court said Smith could again launch a legal challenge for the inheritance.

Smith first gained fame for an advertising campaign for Guess jeans, in which she closely resembled the late Marilyn Monroe. The successful ads featured her image on giant billboards, inside magazines and in department store displays.

"She looked like Marilyn Monroe and was as pretty as Marilyn Monroe. And when you think about it, both have had mysterious deaths," broadcaster Larry King, who interviewed Smith several times, told CNN.

More recently, Smith had her own reality television program called "The Anna Nicole Show," which aired from 2002 to 2004.

Smith was born Vickie Lynn Hogan on Nov. 28, 1967, in Houston. She was one of six children of Donald Eugene and Virgie Hart Hogan.

With files from The Associated Press