Police now say they believe illegal drugs were being made at a home they searched on Albany Street in St. John's last fall.
RNC said officers found chemicals such as sulphuric acid, acetone, hydrochloric acid and a mild hallucinogen in the home back in September.
They entered the home when Brian Moores, 43, was rushed to hospital on Sept. 21. Police then evacuated dozens of houses in the area when they found material that was described as "potentially explosive."
The chemicals that were discovered can be used to make a variety of synthetic drugs, but police said a laboratory analysis was unable to determine exactly which drug was being manufactured.
Officers also found marijuana in the house during the search.
RNC said Brian Moores owned the materials.
He was removed from the home by ambulance and later passed away, so no charges have been laid. Police have not released the cause of death.
His mother told CBC that Moores died from a complication of his diabetes. She said he lived in the house with her and was not operating a drug lab.