Before she died in 2007, Anna Nicole Smith was investigated by the FBI in connection with an alleged murder plot against the son of her late oil tycoon husband, but the former Playboy Playmate was never prosecuted.
According to documents obtained by The Associated Press, the FBI investigated Smith in 2000 and 2001 in a murder-for-hire plot targeting E. Pierce Marshall. Marshall fought to keep Smith from inheriting his father J. Howard Marshall's multi-million dollar estate after he died in 1995, less than a year after marrying Smith.
The case bounced around the courts for years until the Supreme Court unanimously ruled in May 2006 that Smith could pursue her late husband's fortune. The younger Marshall died a month later from an infection. Smith died the following year, in February 2007, from a drug overdose.
Federal agents interviewed Smith on July 3, 2000. When she was told why she was being questioned, the report said, "Smith began crying and denied ever making such plans."
After reviewing the reports, prosecutors determined there was insufficient evidence for the case to go forward.
As part of the probe, the FBI confiscated a .357 Smith and Wesson revolver, a 3 1/2-inch stainless-steel knife and, for unexplained reasons, a black and orange hat described as "Dr. Seuss." All three objects were returned to her about seven months later.
Smith was 26 when she wed the 89-year-old J. Howard Marshall. According to an interview with the younger Marshall, included in the FBI report, Marshall said Smith rarely spent time with his father and that his father complained that she asked for $50,000 to $60,000 twice a week.
Since Smith's death, her lawyer and companion Howard K. Stern and two doctors, Dr. Sandeep Kapoor and Dr. Khristine Eroshevich, have been charged in California with helping the model obtain drugs that ultimately killed her. All have pleaded not guilty.
ABC recently obtained affidavits showing that Smith's doctors had crossed boundaries to indulge in "unprofessional" relationships with their patient.
The documents submitted to a Los Angeles judge in support of search warrants in the case suggest that Smith's psychiatrist Khristine Eroshevich and internist Sandeep Kapoor had relationships "that appeared sexual in nature" with the model, who was found dead in a Florida hotel room.
The medical examiner determined that 39-year-old Smith died after an accidental drug overdose involving nine different medications or an "acute combined drug intoxication."
According to the affidavits, photographs were discovered in the investigation depicting Smith naked with Eroschevich in a bathtub in "intimate embraces" that "constitute unprofessional behavior."
Asked about any sexual relationship with Smith, Eroschevich's attorney Aadam Braun said, "Anna was a dear friend of Dr. Eroshevich. Dr. Eroshevich would never have done anything to hurt her friend."
"Dr. Eroshevich tried her best to help her friend and patient Anna get through a very difficult period following the loss of a child," said Braun. "Although the care might not have been perfect it was consistently guided by Dr. Eroshevich's desire to help Anna cope with this horrific lost and the psychiatric and other medical issues exacerbated by it."
A video, originally aired on "Inside Edition," is also mentioned in the affidavit and is described as showing Kapoor shirtless in a "reclining position" with Smith at a nightclub.