04/05/2007 at 01:50 PM EDT
The doctor who authorized the 11 prescription medications discovered in Anna Nicole Smith's Florida hotel room the day she died is being investigated by the California Medical Board, a rep confirms to PEOPLE.
The Medical Board spokeswoman would offer no details about the investigation of Dr. Khristine Eroshevich – a Los Angeles-based psychiatrist and friend of Smith's who had traveled with her to Florida – except to say that the probe "involved Anna Nicole Smith."
Normally, the Medical Board does not disclose such investigations, but the spokeswoman said Smith's death "was a high-profile case [and] we want to assure the public we are doing our job."
The investigation was first reported by TMZ.com.
While it is not known what quantities of the 11 different drugs had been taken by Smith, more than 600 pills – among them, approximately 450 muscle relaxants – were missing from prescriptions that were filled no more than five weeks before she died on Feb. 8
, according to documents released by Florida's Broward County medical examiner's office on Wednesday, the Associated Press reports.
Eroshevich authorized all the prescriptions found in the hotel room where Smith was found unresponsive shortly before she died, according to the documents from the office of medical examiner Dr. Joshua Perper, who also cited two other doctors who prescribed drugs to Smith.
Calls to Eroshevich in Los Angeles were not returned.
In an autopsy report
released by Florida officials last week, the types of drugs in Smith's system were disclosed – but the remarkable quantity of medications was not revealed until Wednesday's release of the additional records.
The potent sleeping aid chloral hydrate, named a key factor in Smith's death, was prescribed Jan. 2. About two-thirds of the bottle was gone, according to Perper's records. Also shown are 62 tablets of the anti-anxiety drug Valium missing from a prescription filled less than two weeks before Smith's death.
Eight drugs were prescribed in the name of Smith's companion, Howard K. Stern, while none were prescribed in Smith's own name, the documents show. Perper has said all the medications were intended for Smith.
Two attorneys for Stern did not return the AP's calls seeking comment.
Also shown, according to records, were three prescriptions for muscle relaxants found in Smith's hotel room: two for carisoprodol (prescribed Jan. 2 and Jan. 26) and one for methocarbamol, under the brand name Robaxin (prescribed Jan. 2). About 415 of the carisoprodol pills were gone from their containers, as were 33 of the Robaxin pills, according to the documents.
In addition, 79 tablets of the anti-seizure medications Topomax and Klonopin were missing, along with at least two dozen diuretics, antibiotics, antivirals and potassium supplements. Not mentioned in the newly disclosed documents were the powerful painkiller methadone or the anti-anxiety pill Ativan, both of which were found in Smith's system.
Also missing from the report was information on who prescribed human growth hormone, the muscle-building, weight-reducing agent Smith was said to have been taking around the time of her death.
Reporting by FRANK SWERTLOW