An attorney for pain management specialist Dr. Van Vu of Huntington Beach, Calif., told the Los Angeles Times his client would cooperate fully with the investigation.
A Medical Board of California investigator has begun obtaining releases from relatives of the 16 deceased patients of Vu authorizing the board to review their medical records, the newspaper reported Friday.
"The wheels of justice grind slowly but they grind," said Sally Finnila Sloane, whose brother Karl fatally overdosed on a cocktail of drugs in 2007, two of them prescribed by Vu.
Charles Thurber whose 22-year-old daughter Jennifer died of an overdose the same year told the Times the investigation is warranted.
Fatal overdoses involving prescription painkillers and anti-anxiety drugs have risen sharply in the last decade.
The newspaper published a series of articles last year indicating a small cluster of doctors were associated with a disproportionate number of prescription drug overdose deaths.
Vu was linked to more deaths than any other doctor, a Times analysis found.