Conservative watchdog Judicial Watch has filed a Freedom of Information Act lawsuit against the Justice Department for communication records relating to the inception of the FBI’s investigation into Russian interference in the 2016 presidential election, the group announced Thursday.

Judicial Watch said the lawsuit was lodged because the DOJ didn’t adequately respond to a Freedom of Information Act request filed more than a year ago that sought communication records of key U.S. officials dating from January 2016 to May 2017.

The group is seeking: “All records of internal DOJ communications, including emails (whether on .gov or non-.gov email accounts), text messages or instant chats, of officials in the offices of the Attorney General and Deputy Attorney General regarding possible Russian involvement and/or interference in the 2016 U.S. presidential campaign.”

The FBI began an investigation into Russian interference in the 2016 election in July of that year. That investigation eventually evolved into special counsel Robert Mueller’s 22-month inquiry, which ended just last month with the conclusion that President Trump did not collude with the Russians to influence the outcome of the election, according to Attorney General William Barr.

Former FBI Director James Comey was fired in May 2017, and Mueller was appointed by Deputy Attorney General Rod Rosenstein to lead the investigation soon after. There has been much scrutiny over how the initial investigation began and whether the inquiry had any political overtones. Former FBI Deputy Director Andrew McCabe corroborated reports saying Rosenstein told officials that there were discussions about wearing a “wire” to record Trump as well as invoking the 25th Amendment to remove him from office after Comey’s firing.

The Justice Department has denied the claims about Rosenstein, calling them “ inaccurate and factually incorrect.”

Judicial Watch has sued the Justice Department before. Last month, it sued for all of Rosenstein’s communications from around the time of Comey’s firing and Mueller’s appointment. It also sued the DOJ in February for any recordings Rosenstein might have made during meetings at the White House.

In a statement attached to Thursday’s press release, Judicial Watch President Tom Fitton called the investigation “the worst corruption scandal in American history.”

“Americans deserve to know the truth about what the corrupted DOJ and FBI leadership were saying when they were ginning up the bogus Russia investigation,” Fitton said. “It’s no wonder the DOJ and FBI are stonewalling.”