California Attorney General Jerry Brown announced that the Californian raided six locations Friday in a probe into the death of the late Anna Nicole Smith.

Anna Nicole Smith, a Texas native became world famous in 1993, when she was Playboy’s Playmate of the Year. In 1994, she married oil billionaire J. Howard Marshall, when she was 26 and he was 89. Marshall, who was worth $1.6 billion, died 14 months later. His death has lead to a series of legal disputes between Smith and Marshall’s son, E. Pierce Marshall.

Anna Nicole Smith, 39, died in February 8 at a Florida-casino hotel because of an accidental drug overdose, a fatal concoction of medication she was taking for depression, weight loss, anti-aging and for insomnia. Months earlier, her son Daniel, also died because of an overdose of prescription medication

She was buried in the Bahamas on March 2.

California Attorney General Jerry Brown launched an investigation on March 30 after it was discovered that the drugs involved in Smith’s death were prescribed by California’s physicians.

During a press conference he said the probe involved the "prescribing and dispensing practices of several California licensed doctors and pharmacies".

"The Department of Justice today served search warrants at various doctors' offices, billing locations and residences in Los Angeles and Orange County," Brown said.

"The locations that were searched relate to doctors who prescribed medical treatment or prescribed drugs for Anna Nicole Smith or her associates.", Brown added.

The authorities have searched the offices and residences of two of Smith's former doctors, psychiatrist Khristine Eroshevich and physician Sandeep Kapoor, but no charges were filed.

Khristine Eroshevich, who had traveled alongside Smith on her final Florida trip, is considered to be responsible for prescribing all 11 medications that were found in the hotel room where Smith died.

Dr Sandeep Kapoor prescribed methadone for Smith during her pregnancy with her daughter, Dannielynn, according to Dr Joshua Perper, the Broward County, Florida, medical examiner and he has been the target of an investigation by the California Medical Board.

Browne refused to elaborate on what the authorities hope to discover. "We're looking into a number of possible violations, what the specific ones are we're not going to say. We're not going to limit our investigation...We don't want to jeopardize anything by premature statements and speculation,” he said.