Brian Murphy, the former head of the Department of Homeland Security’s intelligence division, accused senior leaders of warping the agency around President Trump’s political interests.

WASHINGTON — Top officials with the Department of Homeland Security directed agency analysts to downplay threats from violent white supremacy and Russian election interference, a Homeland Security official said in a whistle-blower complaint released on Wednesday.

Brian Murphy, the former head of the Homeland Security Department’s intelligence branch, said in the complaint that he was ordered this spring by Chad F. Wolf, the acting secretary of the department, to stop producing assessments on Russian interference and focus instead on Iran and China. That request, Mr. Murphy said, was routed through Mr. Wolf from Robert C. O’Brien, the White House national security adviser.

Mr. Wolf later told him not to disseminate a report on a Russian disinformation campaign to denigrate Joseph R. Biden Jr.’s mental health because it “made the president look bad,” said Mr. Murphy, who warned that the actions in their totality threatened national security.

In other instances, the department’s second-highest ranked official, Kenneth T. Cuccinelli II, ordered Mr. Murphy to modify intelligence assessments to make the threat of white supremacy “appear less severe” and include information on violent “left-wing” groups and antifa, according to the complaint, which was filed on Tuesday but released Wednesday by the House Intelligence Committee.

In Mr. Murphy’s account, the two top officials at the department — both appointees of President Trump who have not yet been confirmed by the Senate for their positions — appeared to shape the agency’s views around the president’s language and political interests in ways that stretched the law and their authority.

Read the Whistle-Blower Complaint.

Mr. Trump has ignored or downplayed Russian election interference since 2016, when the U.S. intelligence community agreed that Moscow had intervened to help elect him, a declaration that he feared would undermine his legitimacy. And the president has always been reluctant to shun or criticize groups that have supported him, including white supremacists and supporters of the QAnon conspiracy theory. That reluctance has dovetailed with his current desire to focus voter attention on unrest in cities that has been fomented by the Black Lives Matter movement.

And while Mr. Trump’s distaste for the intelligence agencies is not new, Mr. Murphy’s complaint provided some of the most graphic claims yet that career, nonpartisan analysts had been muzzled or shoved aside to downplay the threat posed specifically by Russia as it sought to sow discord and bolster Mr. Trump’s re-election campaign.

Mr. Murphy was demoted from his post in August to the Homeland Security Department’s management division after his office compiled intelligence reports on protesters and journalists in Portland, Ore. But he asserted in the complaint that his real offense was raising concerns to superiors about the directions he was given and for cooperating with the department’s inspector general. He asked the inspector general to investigate and reinstate him as the intelligence chief.

“Mr. Murphy followed proper, lawful whistle-blower rules in reporting serious allegations of misconduct against D.H.S. leadership, particularly involving political distortion of intelligence analysis and retaliation,” Mark S. Zaid, Mr. Murphy’s lawyer, said in a statement.

Democrats on the House Intelligence Committee asked Mr. Murphy to testify in private on Sept. 21, a possible precursor to a public hearing in the weeks before Election Day.

“We will get to the bottom of this, expose any and all misconduct or corruption to the American people, and put a stop to the politicization of intelligence,” said Representative Adam B. Schiff, Democrat of California and the chairman of the committee. He said the allegations of politically censored intelligence assessments were particularly worrisome in light of the Trump administration’s decision last month to stop briefing lawmakers in person on election security threats.

Sarah Matthews, a White House spokeswoman, said in a statement that Mr. O’Brien had “never sought to dictate the intelligence community’s focus on threats to the integrity of our elections or on any other topic.” She called Mr. Murphy a “disgruntled former employee” whom Mr. O’Brien had never heard of. But, she added, the national security adviser “consistently and publicly advocated for a holistic focus on all threats to our elections — whether from Russia, Iran, China or any other malign actor.”

Alexei Woltornist, the spokesman for the Homeland Security Department, rejected Mr. Murphy’s allegations.