The Department of Homeland Security has said it will not agree to a congressional panel’s request to interview official witnesses as part of an investigation of the department’s response to protests in Portland, Ore. The congressional investigation has been fueled by allegations from a top DHS official, who has accused the White House of trying to skew intelligence reports to match President Trump’s claims that far-left extremist groups are behind nationwide protests against police violence.

The House Intelligence Committee’s request to interview several DHS officials “will not be accommodated at this time,” Assistant Secretary Beth Spivey wrote to the committee chairman Monday, arguing that the committee had unreasonably broadened its scope after receiving a whistleblower complaint from Brian Murphy, who until recently was in charge of the department’s intelligence office.

Murphy has alleged that senior DHS officials, acting on orders from the White House, have tried to color intelligence reports in ways that favor Trump’s campaign rhetoric. Murphy claimed in a complaint filed last week with the DHS inspector general that the department’s acting secretary, Chad Wolf, instructed him in May to stop reporting Russian interference in the election and to focus his office’s efforts on China and Iran, two countries Democratic lawmakers briefed on intelligence say are not engaged in the same aggressive attempts to influence the elections as Russia.

Spivey said the committee had appeared to base its request to interview more DHS officials on Murphy’s complaint. While declining to make those witnesses available, the department alluded to an email Spivey said Murphy wrote July 25, in which she said he wrote, “The acting secretary [Wolf] has never given me any direction on what to do Regarding [sic] threats” to the election.

The letter from Spivey to committee Chairman Adam B. Schiff (D-Calif.) did not include the full email from Murphy, and it was not clear what else he may have written on the matter.

‘The Department is trying to have it both ways by making only a select few witnesses available to answer a very narrow set of questions and selectively releasing a small amount of documents in an obvious effort to whitewash serious allegations of misconduct by DHS’s leadership, all while refusing to make available other documents and witnesses who can testify to a broader pattern of misconduct and politicization of intelligence,” Schiff said in a statement.

He said the committee could consider “compulsory process” to force the department to cooperate. The intelligence office is part of the broader intelligence community, a collection of agencies including the CIA, and is therefore under the intelligence committee’s jurisdiction.