The death of an Oak Bluffs man is under investigation and his roommate is being charged with heroin trafficking, the Oak Bluffs police said.

James Christopher Walker, 50, was the man found dead, Oak Bluffs police said Friday morning. The cause of death for Mr. Walker, who went by the name Chris, has not been determined, Oak Bluffs police Lieut. Timothy Williamson told the Gazette.

Mr. Walker's roommate, Mathew Hubert, 52, was arrested on drug charges after police searched the residence Wednesday.

According to an Oak Bluffs police report, officers were called to a Barnes Road home just after 9 a.m. Wednesday for a reported dead body. The body was located in an upstairs bedroom, according to the report prepared by Det. Nicholas Curelli. Officers said they observed signs of heroin use, including a syringe and several small wax bags, one of which still had heroin in it, in the immediate area.

The report said police had received information from a confidential source that Mr. Hubert “gets 500 bags of heroin at a time in Holyoke and sells them here.”

Mr. Hubert was visibly shaking, the report said, and said that he had last used heroin a few hours earlier.

After a brief search of his room, Mr. Hubert was arrested on charges of possession of a class A drug (heroin) and possession of a class B drug (Ritalin) and was transported to the county jail.

After receiving a search warrant, officers from Massachusetts state police, Oak Bluffs and Edgartown, along with K-9 Buster, searched the house. Buster showed signs indicating narcotics in Mr. Hubert’s room, the report said, and in the loft attic. Officers located a brown paper bag with a plastic bag inside containing 17 prescription bottles, one of which contained several hypodermic needles. Two packages wrapped tightly in paper were located and found to contain several wax paper bags of a substance suspected to be heroin. Based on the search, Mr. Hubert was also charged with trafficking in a class A substance (heroin).

State police are handling the death investigation.