Michael Miske died of "toxicity of fentanyl and para-fluorofentanyl," the medical examiner’s office said in a statement obtained by AP. The death appears to have been accidental.

Honolulu's medical examiner says a Hawaii crime boss who died in federal detention this month was killed by an opioid overdose

A medical examiner revealed a Hawaii crime boss died of an opioid overdose while in federal detention. Michael Miske, 50, was found unresponsive at the facility on December 1. It was later revealed that he died from "toxicity of fentanyl and para-fluorofentanyl,