The Medical Board of California opened its inquiry of Dr. Sandeep Kapoor in recent days, board spokeswoman Candis Cohen said Thursday.
"We've received some information alleging that Dr. Kapoor may have had some connection with Anna Nicole Smith, and we are looking into that as we would any allegation of physician misconduct," Cohen told The Associated Press.
Smith, who was living in the Bahamas, died Feb. 8 in Florida at 39. The cause is under investigation.
The medical board's physician information Web site lists Kapoor as a 1996 graduate of Boston University School of Medicine who is currently licensed to practice in California. The public-disclosure section contained no postings in the sections for administrative disciplinary actions or citations.
A woman who answered the telephone at Kapoor's listing in the Studio City area of Los Angeles hung up immediately when The Associated Press called to seek comment Thursday.
Among other things, Cohen said, the board was looking into whether it is legal to prescribe drugs for someone using an alias.
Cohen said the board began looking at Kapoor after receiving information about possible misconduct. Cohen declined to describe the allegation in detail or say where it came from, although she said it was connected to Smith.
The review is routine, Cohen said, adding the board is obligated to review all allegations of physician misconduct.
The celebrity news Web site TMZ.com this week published what appeared to be an Aug. 25, 2006, pharmacy receipt for a methadone prescription written by a "Dr. Kapoor, S." to a "Chase, Michelle."
TMZ said "Michelle Chase" was an alias used by Smith, who was born Vickie Lynn Hogan and married the late oil tycoon J. Howard Marshall II.
TMZ also posted an image of a document that appeared to be an invoice dated the same day for an international shipment of methadone from the pharmacy to a "Vicky Marshall" at a post office box in Nassau, Bahamas.
The Web site's story did not say how the documents were obtained.