A man who allegedly referred a heroin user to a dealer who sold him fentanyl has been criminally charged in connection with the overdose death of the buyer.

Scott Reynolds, 22, was arraigned Friday in Bristol Superior Court on charges of manslaughter for the death of a man who overdosed on heroin laced with fentanyl, the Boston Herald reported.

Fentanyl is a synthetic opioid that has been estimated to be 40 to 50 times stronger than street-grade heroin, and significantly increases the risk of an overdose.

Reynolds pleaded not guilty to manslaughter and charges of possession with intent to distribute. 

It's not the first time prosecutors have pressed homicide-related charges for people associated with selling fentanyl to overdose victims. But Reynolds reportedly isn't accused of selling the drugs in this case.

These charges arise from the death of Berkley resident Marc Esperanca, 25, who overdosed in April.

When Esperanca texted Reynolds looking for heroin, Reynolds gave him the address of a dealer, with a warning that the goods were unusually strong, according to the Herald,.

Esperanca was reportedly found dead in his home from an overdose that day.