LAKE ELSINORE, Calif. -- An elderly doctor was arrested Tuesday in connection with the overdose death of a 28-year-old man.

Dr. Wesley Albert, 78, is accused of illegally giving out prescription medication in Riverside and San Diego counties, according to the California Department of Justice.

Albert was arrested on suspicion of involuntary manslaughter in the prescription drug overdose death of patient, Jason Morgan, 28 of Riverside County. Morgan had dozens of bottles of drugs in his room when he died in November, according to authorities. Albert allegedly prescribed large quantities of the muscle relaxant Soma, also known as Carisoprodol, to Morgan.

"He had taken so much Soma, it had really degenerated his heart -- he had heart failure. The medical examiner did the exam and found he had died basically from a heart attack but from also Soma intoxication," said Ernie Limon with the state Department of Justice.

Investigators said 30 bottles of Albert-prescribed narcotics were in Morgan's room at the time of his death.

Officials investigated Albert for ten months after a former patient was arrested in Encinitas in April 2007 for possessing controlled prescription drugs.

Undercover agents said they discovered Albert was running a prescription mill from his room at the Lake Elsinore Casino and Hotel. There officials said they churned out hundreds of prescriptions for dangerous narcotics including Vicodin, Xanax, Soma and Oxycotin.

Special agents allege Albert routinely prescribed more than 5 times the normal quantity of these drugs, sometimes up to 500 pills per person per month, and pocketed between $50 and $100 cash per prescription.