Anna Nicole Smith was using multiple doctors, pharmacies and associates to obtain prescription drugs under false names, according to a testimony at a preliminary hearing.

Jennifer Doss, a special agent with the California Department of Justice pharmaceutical task force, on Friday showed a judge how she traced prescriptions issued in the names of Smith's boyfriend-lawyer, Howard Stern, an assistant of Smith and a series of fictitious names used by Smith over more than two years.

In addition, Homeland Security agent Kenneth Krause described travel records showing multiple flights by Stern and Smith's psychiatrist, Khristine Eroshevich, to and from the Bahamas at times when prescriptions were picked up in California for the celebrity model.

Doss identified documents detailing the movement of controlled substances including Demerol, Dalmane, Lorazepam and methadone.

She said bottles bearing Stern's name were later found in the home of Eroshevich, who is charged with Stern and Dr Sandeep Kapoor of conspiring to illegally provide Smith with controlled substances.

All three have pleaded not guilty. A judge will rule after the preliminary hearing whether they will stand trial.

Stern's lawyer Steve Sadow suggested in cross-examination that some of the medication was legitimately issued to Stern for a back problem and when he had botox injections.

But the prosecution contends that Stern told an agent early in the investigation that his name was used on prescriptions destined for Smith. The California attorney general has described Stern as "the enabler" of drug use by the Playboy model.