A US doctor has been convicted of accepting thousands of dollars in bribes and kickbacks from Insys Therapeutics, in exchange for prescribing the fentanyl spray that the drug manufacturer produced.

Gordon Freedman, of New York, is the fourth medical practitioner to face trial on charges stemming from what prosecutors say was a wide-ranging bribery scheme orchestrated by the now-bankrupt drugmaker that helped fuel the US opioid epidemic.

A federal jury in Manhattan found Freedman guilty of conspiring to violate the Anti-Kickback Statute and conspiring to commit honest services wire fraud, prosecutors said.

Prosecutors alleged that the Arizona-based Insys Therapeutics bribed doctors by retaining them to act as speakers at sham events, ostensibly meant to educate clinicians about its fentanyl spray, Subsys.