Chicago attorney Tina Tchen — who was in contact with Cook County State’s Attorney Kim Foxx before the charges were dropped against former “Empire” actor Jussie Smollett — refused to be served with a subpoena on Wednesday, according to the process server.

Tchen, who previously served as former First Lady Michelle Obama’s chief of staff, refused to accept a subpoena that was issued by former Illinois Appellate Judge Sheila O’Brien.

O’Brien is petitioning for the appointment of a special prosecutor to look into the state’s attorney’s office’s handling of the Smollett case. She is calling for Tchen to attend a May 31 hearing at the Leighton Criminal Courthouse and bring with her copies of “any and all documents, notes, phone records, texts, tape recordings made or received at any time, concerning [Tchen’s] conversations with Kim Foxx in re: Jussie Smollett.”

Edward Ryan, who operates a private investigation firm in the southwest suburbs, said one of his process servers went to Tchen’s law firm in River North on Wednesday, but she refused to come to the lobby to accept the subpoena.

Ryan said the security guard in the building’s lobby would not let the process server upstairs. The guard called Tchen in her office and “she said she knew about” the subpoena, but refused to come down.

“I don’t know why she’d turn it down. She’ll be served eventually,” Ryan said.

Neither Tchen nor the law firm she works at responded to requests for comment Wednesday.

Tchen has previously denied any effort to sway the outcome of the Smollett case. In a statement in March, she said: “Shortly after Mr. Smollett reported he was attacked, as a family friend, I contacted Cook County State’s Attorney Kim Foxx, who I also know from prior work together. My sole activity was to put the chief prosecutor in the case in touch with an alleged victim’s family who had concerns about how the investigation was being characterized in public.”

O’Brien is requesting a special prosecutor to look into the state’s attorney’s decision to abruptly drop disorderly conduct charges against Smollett, who, police said, staged a hate crime attack against himself as a way to enhance his own public profile.

The Chicago Sun-Times reported in February that Tchen passed Foxx’s number to a relative of the actor before the charges were dropped. Foxx has acknowledged that she tried to persuade Police Supt. Eddie Johnson to turn the investigation over to the FBI after the family member expressed concerns regarding leaked information about the investigation — information that media outlets attributed to “police sources.”

After police determined that Smollett was not a victim and allegedly staged the attack, Foxx cited her conversations with the family member and other communications as the reason she recused herself from Smollett’s prosecution.