New details have been released about an RCMP investigation into a fatal drug overdose in southeastern New Brunswick.

Mounties said they were made aware of a sudden death in the community of Jardineville, near Rexton, on July 25.

At the time, investigators said the drug was believed to have been purchased in Elsipogtog First Nation and contained carfentanil, a synthetic opioid that is stronger than fentanyl.

Testing results have confirmed that the substance was a mixture of fentanyl and bromazolam, RCMP said in an update on Friday.

Bromazolam impacts the ability to revive individuals who have overdosed and does not respond to first aid treatments such as naloxone, said police.

New Brunswick Public Health first warned about the dangerous drug in late 2022 after it was detected in blood samples from nine sudden death investigations.

Anyone with information is asked to contact their local police or Crime Stoppers.