In this June 21, 2017 file photo, special counsel Robert Mueller departs after a closed-door meeting with members of the Senate Judiciary Committee about Russian meddling in the election and possible connection to the Trump campaign, on Capitol Hill in Washington. Mueller’s team of investigators is seeking information from the White House related to Michael Flynn’s stint as national security adviser and about the response to a meeting with a Russian lawyer that was attended by President Donald Trump’s oldest son, The Associated Press has learned. (AP Photo/J. Scott Applewhite, File)

WASHINGTON (AP) — Special counsel Robert Mueller’s team of investigators is seeking information from the White House related to Michael Flynn’s stint as national security adviser and about the response to a meeting with a Russian lawyer that was attended by President Donald Trump’s oldest son, The Associated Press has learned.

Mueller’s office has requested a large batch of documents from the White House and is expected to interview at least a half-dozen current and former aides in the coming weeks. Lawyers for the White House are in the process of trying to cooperate with the document requests.

Though the full scope of the investigation is not clear, the information requests make evident at least some of the areas that Mueller and his team of prosecutors intend to look into and also reveal a strong interest in certain of Trump’s actions as president.

A person familiar with the investigation who spoke to The Associated Press on condition of anonymity to discuss an ongoing investigation said investigators want information on, among other topics, a June 2016 meeting at Trump Tower that Donald Trump Jr. attended with a Russian lawyer as well as on the administration’s response to it.

A statement provided to journalists in July, which the White House has said Trump had a hand in drafting, said the meeting was primarily to discuss a disbanded program that used to allow American adoptions of Russian children, but emails released days later by Trump Jr. show that he arranged the encounter with the expectation of receiving damaging information about Hillary Clinton.

Investigators also are interested in White House actions involving Flynn, such as what officials knew about an FBI investigation into him and how they responded to word that his Russian contacts had been scrutinized. Flynn was forced out as national security adviser in February after White House officials concluded he had misled them about his conversations with the Russian ambassador to the United States.

Former Deputy Attorney General Sally Yates has said she warned White House counsel Don McGahn in January that that deception left Flynn and the White House in a compromised position, and that she expected McGahn to take action. That conversation took place two days after FBI agents had interviewed Flynn. But Flynn was not asked to resign until several weeks later, following news reports that said he had discussed sanctions during the transition period with the ambassador, Sergey Kislyak.

Former FBI Director James Comey has said that Flynn was facing an FBI criminal investigation “of his statements in connection with the Russian contacts and the contacts themselves. And so that was my assessment at the time.”

Comey has also said that Trump, in a private Oval Office encounter in February, told him that he hoped he would end the FBI investigation into Flynn. Trump has denied that.

Comey’s own firing in May is also under investigation for potential obstruction of justice, and Deputy Attorney General Rod Rosenstein, who appointed Mueller as special counsel and oversees his work, has been questioned by investigators about the circumstances of that event, according to people familiar with the matter.

A spokesman for the special counsel’s office declined to comment.

Mueller was appointed in May to investigate potential coordination between Russia and the Trump campaign, and potential crimes arising from that probe. Investigators in July raided the home of Trump’s former campaign chairman, Paul Manafort, in a search of tax and banking records and in recent months have served subpoenas related both to Manafort’s business dealings and those of Flynn.

Mueller’s team of investigators includes prosecutors with experience in organized crime, national security and complex financial fraud cases. The primary prosecutor on the White House investigation is James Quarles, who came with Mueller from the WilmerHale law firm and was involved in Watergate prosecutions.

Among the aides expected to be interviewed in coming weeks are McGahn, former press secretary Sean Spicer and former chief of staff Reince Priebus.

In addition to Mueller, several congressional committees, including the Senate Intelligence committee, are investigating Russia’s interference in the presidential election and any possible coordination with Trump associates.

On Wednesday, Twitter confirmed that it would meet next week with staff of the Senate Intelligence committee, which has been scrutinizing the spread of false news stories and propaganda on social media during the election. The panel has heard from Facebook. The committee’s top Democrat, Sen. Mark Warner of Virginia, had said the committee wanted to hear from Twitter as well to learn more about the use of fake accounts and bot networks to spread misinformation.

“Twitter deeply respects the integrity of the election process, a cornerstone of all democracies, and will continue to strengthen our platform against bots and other forms of manipulation that violate our Terms of Service,” the company said in a statement.