PITTSBURGH — A city man is in jail on federal charges he sold heroin in bags marked “Super,” a label authorities said may have been all-too-accurate in a fatal overdose believed to be linked to the drugs, according to a criminal affidavit.

Allen Coleman Jr., 27, of Pittsburgh hasn’t been charged with causing overdoses or deaths, but with possessing heroin with intent to deliver it.

However, a 15-page probable cause affidavit that Drug Enforcement Administration agents filed with the charges says some of the “Super” heroin has been linked to a death last month in neighboring Westmoreland County. Another bag of “Super” heroin tested by a crime lab in a separate investigation showed it contained heroin and fentanyl, a powerful painkiller, the affidavit said.

The DEA “is currently in the process of determining whether ‘Super’ stamp bags are associated with any other recent overdose deaths in Western Pennsylvania,” according to the affidavit.

Coleman’s defense attorney, James Wymard, said Wednesday he hadn’t had a chance to meet with the defendant.

The bulk of the information in the affidavit comes from a convicted heroin dealer who was once sentenced to nearly 22 years in prison, but had that cut to 10 years. That person, who is not named, is now serving 10 years’ probation. He violated that probation and began cooperating with the DEA last year “with the hope of reducing the ultimate sentence received” for his new drug offenses and the probation violation, the affidavit said.

The informant told agents Coleman supplied him with 30 to 40 bricks of heroin every 2-3 days since last January. A brick is 50 “stamp” or individual dose bags of heroin.

Coleman supplied the informant with heroin stamped “Super” for the past year, and also some marked “Angry Ducks,” the affidavit said.

The “Super” heroin has been linked to an overdose of a 37-year-old man in Westmoreland County on Dec. 15. No other details of that overdose are listed.