OKLAHOMA CITY (AP) — Longtime Oklahoma County Sheriff John Whetsel is announcing his retirement just months after his re-election amid an ongoing investigation into his office's finances.

Whetsel submitted his letter of resignation on Wednesday, saying he believes new leadership is required to solve problems with the jail and "overall funding" of the office.

A scathing audit of Whetsel's office released in November found the office didn't pay contracts for inmate health care and spent about $900,000 on vehicles even though its financial obligations hadn't been met. District Attorney David Prater had launched a criminal investigation into the audit findings.

A Democrat, Whetsel was first elected sheriff of the state's largest county in 1997. He was re-elected in November with nearly 52 percent of the vote.