Unsealed this week in Los Angeles, court documents allege that Anna Nicole's psychiatrist faxed a prescription to a pharmacy for a range of different drugs for the former Playboy Playmate. The prescription included an anti-inflammatory drug, two different types of sedatives and a muscle relaxer, as well as four bottles of a painkiller referred to as "hospital heroin" and 300 tablets of methadone.

The pharmacist who refused to fill the prescription later described it as "pharmaceutical suicide", an affidavit states.

Court documents say the drugs were prescribed by Anna Nicole's psychiatrist, Dr Khristine Eroshevich, and internist Dr Sandeep Kapoor, following the death of Anna Nicole's son, Daniel, and the birth of her daughter, Dannielynn.

Anna Nicole's sister, Donna Hogan, said in a statement in 2007 that the death of Anna Nicole's son, Daniel, "left [Anna Nicole] deeply saddened, a sadness she hid from everyone".

Less than five months after Daniel's death in the Bahamas, Anna Nicole died of a prescription drug overdose. At the time of her death she reportedly had prescriptions for 44 different medications under at least nine aliases.

One affidavit states that Dr Eroshevich also tried to obtain chloral hydrate for Anna Nicole after Daniel's death and the drug was described by the pharmacist as an out-of-date insomnia treatment. "I wouldn't give her chloral hydrate unless you want your picture on the front page of the National Enquirer," the pharmacist reportedly told Dr Eroshevich.

Dr Eroshevich was allegedly later told by retired toxicologist Dr Greg Thompson that chloral hydrate "might work for a drug addict under supervised care or with a dying cancer patient in a hospital or 'if you were going to kill someone'," California Department of Justice special agent, Jennifer Doss, wrote in an affidavit.

Court documents also allege there were photographs of Dr Eroshevich and video footage of Dr Kapoor engaging in sexual behaviour with Anna Nicole. Both doctors deny any inappropriate conduct.

While a Florida medical examiner found Anna Nicole's death was accidental, in March 2009 Dr Eroshevich, Dr Kapoor and Howard K Stern, Anna Nicole's boyfriend at the time, were all charged with supplying addictive prescription drugs to the reality TV star.

All three have pleaded not guilty to conspiring to "commit the crimes of prescribing, administering and dispensing controlled substances to an addict" and "unlawfully prescribing a controlled substance", the Los Angeles Times reported in March 2009. A preliminary hearing is scheduled for next month.