The Department of Homeland Security’s chief watchdog is calling for disciplinary action against a Trump administration political appointee who has refused to cooperate with an investigation into alleged retaliation against career civil servants, according to a memo released Thursday.

Christine Ciccone, a former senior official at the State Department and now an assistant secretary of legislative affairs at DHS, has failed to agree to an interview with investigators “despite repeated requests made to both her and her attorney over many months,” DHS Acting Inspector General John Kelly wrote to Secretary Kirstjen Nielsen in a Feb. 13 memo.

The State Department Office of Inspector General said a senior official’s refusing to submit to an interview is “unprecedented.”

That office is looking into allegations of retribution against career State Department employees, and has tried to speak with Ciccone as a “key witness” in that inquiry since September, Kelly wrote in a memo released by three Democratic lawmakers.

Multiple whistleblowers inside the department have contacted congressional committees alleging politically-motivated personnel decisions during Ciccone’s time as deputy chief of staff to former Secretary of State Rex Tillerson, the lawmakers said in a statement.

The inspector general’s office at the State Department has “documentary evidence demonstrating Ms. Ciccone’s involvement in personnel actions against at least three career employees,” the office told congressional committees Monday.

But it could not finish the review as it had not been able to interview Ciccone, according to the lawmakers’ statement.

Kelly recommended Secretary Nielsen discipline Ciccone due to her failure to cooperate.

U.S. Secretary of Homeland Security Kirstjen Nielsen speaks at the press briefing at the White House in Washington on June 18, 2018.Brendan Smialowski / AFP – Getty Images file

The appointee’s response “sets a dangerous precedent contrary to the fundamental tenants” of the law establishing government inspector generals, and carries “the potential to undermine our critical oversight function,” he wrote.

When asked about the memo, the Department of Homeland Security did not say whether Nielsen would take any disciplinary action against Ciccone.

The secretary “is reviewing the issue,” DHS Press Secretary Tyler Houlton told NBC News in an email.

“Christine Ciccone is an exceptional member of the DHS team and has helped advance…