WILKES-BARRE, Pa.—An informant who helped the federal government bring down a reputed northeastern Pennsylvania mob boss has died.

Frank Pavlico III of Clarks Summit died Wednesday at age 43, one day after appearing in a Wilkes-Barre courtroom on an arrest warrant stemming from a South Carolina fraud case.

Federal probation officers say Pavlico hanged himself. He was not in custody at the time.

Pavlico once wore a wire for the government and recorded conversations with William D'Elia (de-LEE'-ah). Prosecutors say that when D'Elia found out Pavlico was cooperating, the reputed mob boss tried to have him killed. D'Elia pleaded guilty in 2008 to witness tampering and conspiracy to launder drug money and is in prison.

Pavlico served 10 months in federal prison in 2008 on a money laundering charge.