The embattled State Department Inspector General, who has been accused of impeding a Justice Department investigation of Blackwater Worldwide, announced his resignation Friday to colleagues.

Howard Krongard revealed his departure to coworkers at the department on Friday, said Gonzalo Gallegos, a department spokesman.

Gallegos offered no other details, including when Krongard's departure takes effect.

"We thank him for his service," Gallegos said.

Blackwater Worldwide — a private contractor that protects U.S. diplomats in Iraq — is alleged to have smuggled weapons into the country. In November, Krongard was forced to recuse himself from any inquiries into Blackwater after it was disclosed that his brother had joined the company's advisory board.