OLD TOWN, Maine — The man law enforcement officials say died from injuries suffered in a methamphetamine lab explosion last week and whose body was discovered two days later has been identified as a someone with prior convictions related to meth manufacturing, according to police.

Jeffrey Miller, 50, recently had been released from jail after serving a sentence for making methamphetamine on Hammond Street in Bangor, Stephen McCausland, Maine Department of Public Safety spokesman, said Monday.

The Old Town meth lab explosion occurred around 10 p.m. on April 24 in an upstairs apartment at 178 Brunswick St., and a man with injuries to his face fled the scene, the downstairs neighbor who called 911 reported.

Residents of 465 Brunswick St. found Miller’s body there on April 26, McCausland said.

The cause and manner of Miller’s death are both pending further toxicology tests, Mark Belserene, spokesman for the state medical examiner’s office, said Monday.

Four people in the apartment where the meth lab was discovered have been charged.

The upstairs apartment where the meth lab explosion occurred was rented by Jason Smith, 38, and Carrie Ballanger, 31. Don Dube, 47, and Susan Smith, 36, who are dating were crashing there, it was revealed in court on Friday. All four are charged with aggravated unlawful operation of a meth lab, a Class A felony, and bail was set at $10,000 for each during their appearance at the Penobscot Judicial Center. All four remained at Penobscot County Jail in Bangor on Monday.

Maine Drug Enforcement Agency agents in November 2015 executed a search warrant at Miller’s Bangor apartment on Winter Street and found 17 used “one pot” vessels, or soda bottles used to make meth.

A confidential informant allegedly told Bangor police at the time that Miller was “cooking at least four times a day and … selling at night.” The informant also told police that Miller “rides a bicycle down to Pickering Square where he sells meth to kids” for $200 a gram. Miller also allegedly gave people money or drugs in exchange for their purchasing pseudoephedrine products at local pharmacies. Pseudoephedrine is the main ingredient that can be mixed with household chemicals and lithium from batteries to make methamphetamine.

When the MDEA caught up with Miller, he was living in Deer Isle and agents found a meth lab at that residence as well, McCausland said.

Maine drug agents and police investigated only one meth lab in 2009, but that number jumped to 56 in 2015 and 125 last year.

The Old Town incident marked the 20th time MDEA agents have been called to investigate a possible meth-making operation so far this year, according to McCausland.