A White House whistleblower told lawmakers senior Trump administration officials overturned at least 25 security clearance denials despite “serious disqualifying issues.” According to a memo released Monday, Tricia Newbold, who works in the White House Personnel Security Office, told the House Oversight and Reform Committee that the individuals had been flagged by her office over concerns including blackmail, conflicts of interests, criminal conduct and foreign influence.

The chair of the Oversight Committee, Elijah Cummings, indicated he would seek to subpoena Carl Kline, who served as Newbold’s supervisor and overruled her denials. Newbold said she was subject to retaliation for refusing to issue the clearances, including a 14-day suspension without pay.

The White House has previously come under fire for its handling of security clearances. Reports emerged earlier this year that President Trump pressured his former Chief of Staff John Kelly to grant clearances for his daughter Ivanka and his son-in-law Jared Kushner, despite the objections of intelligence officials. Ivanka Trump and Jared Kushner are reportedly included in the group of 25 individuals Newbold raised.