Neither DHS nor Maher immediately responded to a request for comment.
The subpoenas issued Tuesday also give DHS until Oct. 6 turn over previously requested documents relevant to the Intelligence Committee’s investigation of Murphy’s complaint.
In a complaint provided to the congressional Intelligence committees earlier this month, Murphy accused acting DHS Secretary Chad Wolf and acting deputy Ken Cuccinelli of pressuring him to ignore or water down evidence of Russia’s malign activity in the United States and play up evidence pertaining to Iranian and Chinese efforts to meddle in November’s election.
Murphy also alleged that political appointees in the department sought to play down white supremacist violence to reinforce President Donald Trump’s emphasis on left-wing extremism.
According to the complaint, Murphy says he was demoted from his post leading the Intelligence and Analysis office, a branch of the intelligence community, as retribution for raising concerns about the alleged political pressure.
DHS and the White House have forcefully denied Murphy’s claims, but Schiff has accused the department of intentionally slow-walking the approval of security clearances for one of Murphy’s attorneys, therefore forcing his testimony to be delayed twice.
Murphy himself was already under investigation by Schiff’s committee for allegations that he deployed the department’s intelligence resources to track journalists covering protests in Portland, Ore., earlier this summer.
Daniel Lippman contributed to this report.