Douglas S. DePodesta, the special agent in charge of the FBI Chicago field office, was pushed to retire after disagreements with the local US Attorney Andrew Boutros, according to two people familiar with the situation.

Several people familiar with the retirement told CNN they didn’t believe one single dispute lead to the departure, but rather a series of them.

DePodesta planned to begin clearing out his office on Wednesday, according to one of the sources.

None of the people about DePodesta’s retirement were authorized to speak to the media.

The Justice Department referred questions to the FBI. The FBI declined to comment.