The Justice Department has begun taking steps to investigate former president Donald Trump’s removal of presidential records to Mar-a-Lago — some of which were labeled “top secret,” people familiar with the matter said.

The people, who spoke on the condition of anonymity to discuss the sensitive matter, said the probe remained in the very early stages. It’s not yet clear if Justice Department officials have begun reviewing the materials in the boxes or seeking to interview those who might have seen them or been involved in assembling and moving them.

The department is facing increasing political pressure to disclose its plans in the case. On Thursday, House Oversight Committee Chairwoman Carolyn B. Maloney (D-N.Y.) accused the Justice Department of obstructing her committee’s investigation into the 15 boxes of records Trump took to his estate in Palm Beach, Fla.

In a letter addressed to Attorney General Merrick Garland, Maloney alleges that the Justice Department is “interfering” with the investigation by preventing the National Archives and Records Administration from handing over a detailed inventory of the contents of the recovered boxes.

If the department is planning an investigation, that might explain why it would not want lawmakers getting an inventory of the materials.

It is unclear to what extent the Justice Department already has assessed the contents of the boxes, which the National Archives arranged to retrieve from Mar-a-Lago in January — including documents clearly marked as classified, The Washington Post previously reported. The Justice Department, though, has been in touch with the Archives about moving its own inquiry forward, people familiar with the matter said.

Addressing the matter previously, Garland said the department would “do what we always do under these circumstances — look at the facts and the law and take it from there.”

Trump’s spokesman in the past has defended his handling of the records. “It is clear that a normal and routine process is being weaponized by anonymous, politically motivated government sources to peddle Fake News,” Taylor Budowich said in a statement in February.

In her letter Thursday, Maloney said her committee needed further explanation as to why the Justice Department was blocking its request for an inventory of the records.

“The Committee does not wish to interfere in any manner with any potential or ongoing investigation by the Department of Justice,” Maloney wrote. “However, the Committee has not received any explanation as to why the Department is preventing NARA from providing information to the Committee that relates to compliance with the [Presidential Records Act], including unclassified information describing the contents of the 15 boxes from Mar-a-Lago.”

An FBI spokeswoman told The Post, “We can neither confirm nor deny the existence of an investigation.”

The National Archives sent a letter to the committee at the end of last month saying that on the basis of the Archives’ “consultation” with the Justice Department, the Archives was unable to “provide any comment” and fulfill the committee’s request. It instead referred the committee to the DOJ’s Office of Legislative Affairs for any further questions.

Maloney asked the Justice Department to tell the committee by April 14 whether it “will inform NARA that it may fully cooperate with the Committee’s inquiry, including by providing the requested inventory of documents recovered from Mar-a-Lago.”