A senior official has resigned his job at Denver International Airport after spending more than three months under investigation, an airport spokesperson confirmed.

Robert Kastelitz, DIA’s chief information officer and senior vice president for technologies, was placed on investigatory leave Feb. 27. DIA has declined to identify the subject of its investigation or release any information.

Kastelitz’s job included overseeing information technology services and several related contracts.

“The investigation has not been completed or resolved at this time,” DIA spokesperson Stacey Stegman told The Denver Post this week.

Kastelitz sent a brief email to several officials Monday notifying them he intended to retire, with his resignation effective the same day. He had been on paid leave, drawing his $204,000 annual salary, according to the airport.

Kastelitz earlier told The Post that airport officials “never gave me a reason” for the investigation. Reached Wednesday, he said he still had not received any indications.

When asked about his retirement decision, he said: “I enjoyed 10 years at the airport. And the airport is constantly changing, and I don’t agree with the direction they’re going — and decided to retire.”