(CNN) A Cook County circuit court judge ruled Friday that the attorney investigating the handling of actor Jussie Smollett's case will remain the special prosecutor despite his 2016 campaign donation to the state's attorney who dropped charges against the actor.

Former US Attorney Dan Webb was appointed by Judge Michael Toomin in August to investigate how local prosecutors handled the TV actor's case. Webb's appointment means he's given the authority and time to examine why Cook County State's Attorney Kim Foxx dropped 16 disorderly conduct charges against Smollett after a high-profile Chicago Police investigation that lasted several weeks using dozens of investigators.

The conflict of interest issue arose Monday when Webb filed a motion for a status hearing because it was brought to his attention that he donated $1,000 to Foxx in an October 2016 fundraiser.

Webb wrote in the motion that he "did not know Kim Foxx, and to the best of my recollection, I had never met Kim Foxx and never had any communications with her."

"I did not disclose to Judge Toomin that I had ever made a political contribution to Ms. Foxx because, at the time I was talking to Judge Toomin, I had no recollection of ever making a political contribution to Kim Foxx," Webb wrote.

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