Whether the scandal grows to engulf other parts of the university administration could hinge in part on an internal investigation opened in response to the article.

Citing interviews with associates of Dr. Puliafito as well as videos and photos, The Los Angeles Times chronicled a series of troubling accusations. Among them:

• Dr. Puliafito commonly used hard drugs. At times, he was seen swallowing what was said to be an ecstasy pill and inhaling smoke from a methamphetamine pipe.

• A man who was living in an addiction treatment facility said Dr. Puliafito, a friend of his, had given him meth.

• A woman who worked as a prostitute said she and Dr. Puliafito, who is married, had become “constant companions” after meeting in 2015.

Dr. Puliafito resigned as dean last year not long after the woman, Sarah Warren, overdosed while the pair were at a Pasadena hotel. Yet he continued to serve on the medical school’s faculty.