A sheriff's deputy in Indianapolis bit off more than he could chew from a local McDonald's — or at least more than he could remember.

The Marion County Sheriff's Office launched an investigation last week after one of its officers said he suspected someone had taken a bite out of a McChicken sandwich he purchased at a McDonald's outside downtown Indianapolis before he completed the sale.

The officer, identified only as "DJ" by NBC affiliate WTHR, is a regular at the restaurant and told the station he did not make the discovery until hours into his shift at the Marion County Jail.

"I started to warm up my McChicken and I noticed several small bites," the officer said. "I know I didn't eat it. No one else was around. I said, 'You know what? I am going to the McDonald's to see if they can get that taken care of.'"

The officer returned to the McDonald's and spoke to a supervisor who offered him free food, which he said he "didn't care anything about."

"I just wanted to find out who the person was and they deal with that person in an appropriate way," he told WTHR.

A representative for McDonald's declined comment Monday, deferring all questions to the sheriff's office.

On Friday, the sheriff's office announced the findings of its investigation: DJ forgot he had taken a bite out of the McChicken sandwich at the start of his shift.

“Last week, a Marion County Sheriff’s Office employee purchased a McChicken sandwich from the McDonald’s location at 3828 W Morris Street, Indianapolis," the sheriff's office told NBC News in a statement Monday. "The employee took a bite out of the sandwich upon starting his shift at the Marion County Jail, then placed it in the refrigerator in a break room."

The officer returned nearly seven hours later "having forgotten that he had previously bitten the sandwich," the sheriff's office said, adding DJ "wrongly concluded that a McDonald’s employee had tampered with his food because he is a law enforcement officer."

The sheriff's office said McDonald's assisted in its investigation and that staff at the fast-food franchise "in no way tampered with the employee’s food."

DJ has since formally apologized to McDonald’s, the sheriff's office said.