WASHINGTON — Apple told Donald F. McGahn II, the White House counsel to former President Donald J. Trump, last month that the Justice Department had subpoenaed information about an account that belonged to him in February 2018, and that the government barred the company from telling him at the time, according to two people briefed on the matter.
Mr. McGahn’s wife received a similar notice from Apple, said one of the people, who spoke on the condition of anonymity to discuss a sensitive matter.
It is not clear what F.B.I. agents were scrutinizing, nor whether Mr. McGahn was their specific focus. In investigations, agents sometimes compile a large list of phone numbers and email addresses that were in contact with a subject, and seek to identify all those people by using subpoenas to communications companies for any account information like names, computer addresses and credit card numbers associated with them.
Still, the disclosure that agents secretly collected data of a sitting White House counsel is striking as it comes amid a political backlash to revelations about Trump-era seizures of data of reporters and Democrats in Congress for leak investigations. The president’s top lawyer is also a chief point of contact between the White House and the Justice Department.
Under Justice Department policy, gag orders for subpoenas may be renewed for up to a year at a time, suggesting that prosecutors went to court several times to prevent Apple from notifying the McGahns earlier.
Spokespeople for Apple and the Justice Department did not immediately respond to requests for comment. A lawyer for Mr. McGahn declined to comment.
Apple told the McGahns that it received the subpoena on Feb. 23, 2018, according to a person briefed on the matter. The other person familiar with the matter said the subpoena had been issued by a grand jury in the Eastern District of Virginia.
It is not clear why prosecutors obtained the subpoena. But several notable events were occurring around that time.
One of the roughly concurrent events was that the federal court in the Eastern District of Virginia was the center of one part of the Russia inquiry led by the special counsel, Robert S. Mueller III, that focused on Paul Manafort, the onetime chairman of the 2016 Trump presidential campaign.
Because Mr. McGahn had been the top lawyer for the Trump campaign in 2016, it is possible that he had been among those in contact with someone whose account the Mueller team was scrutinizing in that period.
Notably, Mr. Manafort had been hit with new fraud charges unsealed the day before the subpoena. Subsequent developments revealed that Mr. Mueller’s investigators were closely scrutinizing some of his communications accounts in the days that followed.
Another roughly concurrent event was that around that time, Mr. Trump had become angry at Mr. McGahn over a matter a related to the Russia investigation, and that included a leak.
In late January 2018, The New York Times had reported, based on confidential sourcing, that Mr. Trump had ordered Mr. McGahn the previous June to have the Justice Department remove Mr. Mueller, but Mr. McGahn had refused to do so and threatened to resign. The Washington Post confirmed that account soon after in a follow-up article.
The Mueller report, and Mr. McGahn himself in private testimony before the House Judiciary Committee this month, described Mr. Trump’s anger at Mr. McGahn after the Times article, including trying to get him to make a statement falsely denying it. Mr. Trump told aides that Mr. McGahn was a “liar” and a “leaker,” according to former Trump administration officials. In his testimony, Mr. McGahn said that he had been a source for The Post’s follow-up to clarify a nuance — to whom he had conveyed his intentions to resign — but he had not been a source for the original Times article.
There are reasons to doubt that Mr. McGahn was the target of any Justice Department leak investigation stemming from that episode, however. Among others, information about Mr. Trump’s orders to have Mr. Mueller removed does not appear to be the sort of classified national-security secret that it can be a crime to disclose without authorization.
Yet another roughly concurrent event is that the subpoena to Apple that swept up Mr. McGahn’s information came shortly after another one the Justice Department had sent to Apple on Feb. 6, 2018, for a leak investigation related to unauthorized disclosures of information about the Russia inquiry, ensnaring data on congressional staff members, their families and at least two members of Congress.
Among those whose data was secretly seized under a gag order, and who were only recently notified, were two Democrats on the House Intelligence Committee: Eric Swalwell and Adam B. Schiff, both of California. Mr. Schiff, a sharp political adversary of Mr. Trump, is now the panel’s chairman. The Times first reported on that subpoena last week.
Many questions remain unanswered about the events leading up to the politically sensitive subpoenas, including how high they were authorized in the Trump Justice Department and whether investigators anticipated or hoped that they were going to sweep in data on the politically prominent lawmakers. The subpoena sought data on 109 email addresses and phone numbers.
In that case, the leak investigation appeared to have been primarily focused on Michael Bahar, then a staffer on the House Intelligence Committee. People close to Jeff Sessions and Rod J. Rosenstein, the top two Justice Department officials at the time, have said that neither knew that prosecutors had sought data about the accounts of lawmakers for that investigation.
It remains murky whether agents were pursuing a theory that Mr. Bahar had leaked on his own or whether they suspected him of talking to reporters with the approval of the lawmakers. Either way, it appears they were unable to prove their suspicions that he was the source of any unauthorized disclosures; the case has been closed and no charges were brought.
Katie Benner and Adam Goldman contributed reporting.