A Baltimore drug kingpin who inspired characters on HBO's "The Wire" has died while serving a term in federal prison in North Carolina.

Baltimore Health Department spokesman Sean Naron confirmed on Tuesday that 54-year-old Nathan Barksdale died in a medical prison in Butner. Naron did not know exactly when Barksdale died, or how. The death was first reported in The Baltimore Sun.

Barksdale ran a heroin-dealing operation in Baltimore in the 1980s, and served 15 years in state prison on a battery charge. "The Wire" creator David Simon has said Barksdale served as inspiration for aspects of some of the show's characters.

Wood Harris, who's expected to star in long-delayed basketball biopic "Sweetwater," played Avon Barksdale on the HBO series.

In recent years, the real Barksdale worked with Safe Streets, an anti-violence program run by the Health Department.

In 2014, however, he pleaded guilty to participating in a drug conspiracy and was sentenced to four years