(CNN) The Chicago police union is again calling for a federal investigation into State's Attorney Kim Foxx to determine the extent of her involvement with the Jussie Smollett case.
Kevin Graham, president of the Chicago Fraternal Order of Police, said the demand is based on news reports about text messages between Foxx and an attorney about, according to him, "diverting the case from Chicago police department to a federal investigation."
Foxx, the state's attorney for Cook County, recused herself from the Smollett investigation in mid-February. She told CNN affiliate WLS on Wednesday that she did so when it was clear Smollett's role in the case was changing from victim to suspect.
She told the Chicago station she did so after consulting with her department's chief ethics officer.
Smollett was charged about a week later with 16 counts of filing a false police report, a Class 4 felony. Foxx said she was never actively involved in the case because the crime was the lowest level of felony, but she did get updates until an email from the chief ethics officer went out to her staff, instructing them not to include her in discussions about the investigation.
Graham, who spoke to reporters after prosecutors announced they were dropping charges against Smollett, said he originally made the request to the US Department of Justice last week. He also has asked federal investigators to look into a letter sent to Smollett days before he alleged he was attacked on a Chicago street.
"We're doubling down on that. We want to make sure that the Justice Department takes a very hard look with that case and what went on today," he said.
Text messages obtained by CNN through an open records request show Smollett family friend Tina Tchen -- a former chief of staff for first lady Michelle Obama and a lawyer -- reached out to Foxx on February 1. Tchen wrote the family had "concerns about the investigation."
Foxx emailed Tchen saying in part, "Spoke to Superintendent (Eddie) Johnson. I convinced him to (r)each out to FBI to ask that they take over the investigation. He is reaching out now and will get back to me shortly."
Later another person, identified by Foxx's office as a family friend, asked the prosecutor whether they could talk on the phone. She says Tchen gave her Foxx's number.
Hours later, Foxx texts the unidentified family friend that she "spoke to the (police) superintendent earlier, he made the ask. Trying to figure out the logistics."
The person responds: "Omg this would be a huge victory."
Foxx and the family friend exchanged text messages until February 13, Cook County State Attorney's Office spokeswoman Tandra Simonton said earlier this month.
Foxx told WLS that when she spoke to Smollett's family members, he was still thought to be the victim of a possible hate crime, and it is not unusual for her speak to the families of victims. She thought there was a lot of misinformation in the media, and that if the FBI were to handle the case that would cut down on the number of leaks in the case.
Efforts to get a comment from the Department of Justice were unsuccessful.