Two sources with direct knowledge of a state audit of the Mississippi Bureau of Narcotics say part of the probe is focused on potential misuse of state property by the agency's director, John Dowdy.

The probe began as a routine check of agency accounting conducted by the state auditor's office.

Asked about the audit Thursday, Dowdy said in a text message, "It is a routine compliance audit that is incomplete and ongoing at this time."

The state auditor's office declined to comment.

Confirmation of the audit came just hours after news broke that Dowdy's chief of staff, Allison Killebrew, had resigned Tuesday. She claimed in a resignation letter that she was forced out of her job as MBN's top attorney and suggested Dowdy had been pressuring department attorneys to act like his own personal lawyers.

One source said Killebrew's resignation is believed to be linked to the audit.

Killebrew declined to comment.

Dowdy has been the director of MBN since November 2016. Previously, he worked at the U.S. Attorney’s Office for the Southern District of Mississippi.

Killebrew sent her resignation letter to Dowdy on Tuesday. The Clarion Ledger obtained the letter Thursday morning.

When asked for comment about Killebrew's resignation, Dowdy texted, "MBN does not comment on personnel matters."

According to her resignation letter, Dowdy had presented her with a pre-written resignation letter, but she wanted to write her own.

"You seem to misunderstand that the MBN legal office does not represent you," Killebrew wrote. "...While you may have lost faith in me, I lost faith in your ability to do the right thing for the employees of MBN and the state of Mississippi many months ago."

Allison Killebrew letter of resignation from Mississippi Bureau of Narcotics

Contact Giacomo "Jack" Bologna at 601-961-7282 or gbologna@gannett.com. Follow him on Twitter @gbolognaCL.