This post has been updated.

Vice President Pence's office confirmed to The Washington Post on June 15 that Pence has hired a personal attorney to respond to inquiries from special counsel Robert Mueller as part of his investigation into Russian interference in the 2016 election.

That adds to the number of current and former Trump associates that are being investigated by Congress, the FBI or Mueller — making it a little bit difficult to keep track of who has been contacted by investigators, whether they're personally being investigated, what they're being investigated for and whether they've cooperated.

Which current and former Trump associates are being investigated? Here's what we know:

Vice President Pence

What we know: Pence hired a personal attorney to deal with the Russia investigation, his office confirmed to The Washington Post's Ashley Parker on June 15:

“I can confirm that the Vice President has retained Richard Cullen of McGuireWoods to assist him in responding to inquiries by the special counsel,” said Jarrod Agen, a Pence spokesman, in an emailed statement. “The Vice President is focused entirely on his duties and promoting the President’s agenda and looks forward to a swift conclusion of this matter.”

The key words there are, “to assist him in responding to inquiries by the special counsel.” There's no suggestion that Pence is personally under investigation here, but his lawyer confirms that special counsel Robert Mueller has made inquiries, presumably either for documents, or to question Pence in person.

Michael Cohen, President Trump's personal attorney

Congressional investigators asked President Trump's personal attorney, Michael Cohen, to turn over documents related to potential contacts with Russia and testify in front of Congress — but on May 30, Cohen said he'd refused to do so. (Peter Stevenson/The Washington Post)

What we know: Cohen, like several other Trump aides, was first asked to turn over any documents he possesses related to contacts with Russian officials, and to testify in front of congressional committees. Then, on May 31, the House Intelligence Committee issued a subpoena to Cohen and his law firm, Michael D. Cohen and Associated PC, compelling Cohen

His name came up in a report published by BuzzFeed News in January, in which he was said to have traveled to Prague to meet with Russian officials. Cohen adamantly denied that he had ever been to Prague, and White House press secretary Sean Spicer expanded on that at a news conference:

Michael Cohen, who is said to have visited Prague in August and September, did not leave or enter the United States during this time. We asked him to produce his passport to confirm his whereabouts on the dates in question and there was no doubt that he was not in Prague.

In fact, Mr. Cohen has never been in Prague. A new report actually suggests that Michael Cohen was at — at the University of Southern California with his son at a baseball game. One report now suggested apparently it's another Michael Cohen.

What Cohen has turned over to investigators: So far, not much. Cohen confirmed to ABC News on May 30 that congressional investigators have asked him to turn over information, but said he wouldn't comply.

“I declined the invitation to participate, as the request was poorly phrased, overly broad and not capable of being answered,” he told ABC.

But that was before the subpoena. Cohen changed his tune on May 31.

“I have nothing to hide,” he told NBC. “I will make myself available and I am more than happy and willing to testify but they have to be specific.”

Michael Flynn, former national security adviser

If you're having trouble keeping track of former National Security Adviser Michael Flynn's ties to Russia and Turkey, here's what you need to know. (Gillian Brockell/The Washington Post)

What we know: Flynn resigned from his post as national security adviser just 24 days into the Trump presidency. His resignation came after then-Deputy Attorney General Sally Yates told administration officials that Flynn had been “compromised” by Russian officials who might attempt to blackmail him.

Flynn seemingly had a cozy relationship with high-ranking Russian officials. He “collected almost $68,000 in fees from Russia-related entities in 2015,” the year before the election, per The Washington Post's Rosalind S. Helderman and Tom Hamburger. Most of that money came from a speech in Moscow at which Flynn was seated near Russian President Vladimir Putin.

But Flynn reportedly told investigators that he was paid for the speech by U.S. companies — an assertion one congressional Democrat called a “lie.” Flynn also had multiple contacts with Russian officials during the 2016 campaign, even after being told that his contacts with Russian Ambassador Sergei Kislyak were risky. U.S. intelligence officials were apparently concerned that Flynn didn't understand Kislyak's motives in meeting with him.

On June 2, Reuters reported that special counsel Robert Mueller will expand his investigation to include Flynn's work as a lobbyist for a Turkish businessman, which he did while serving as an adviser on Trump's 2016 campaign.

What Flynn has turned over to investigators: Flynn offered to testify in exchange for immunity in March, but Congress didn't bite. Then, the Senate Intelligence Committee issued a subpoena in May, compelling Flynn to testify and turn over documents. He refused, saying he would invoke the Fifth Amendment.

Then, on May 30, The Washington Post's Karoun Demirjian reports, he decided to hand over documents to the committee. Demirjian writes:

After Flynn’s lawyers rejected the committee’s initial subpoena for personal records detailing any and all communications Flynn had with Russian officials, committee leaders turned to his businesses, arguing, in the words of Mark R. Warner (D-Va.), the panel’s vice chairman, that “a business does not have the right to take the Fifth.”

The narrowed request focuses more closely on documents that the committee thinks exist. But it is not clear if Flynn’s willingness to comply with the new subpoenas means the committee will be satisfied with the documents he turns over — or whether those documents will do anything to prove or disprove allegations that Flynn had improper contacts with Russian officials while acting as a surrogate for President-elect Trump.

The House Intelligence Committee issued its own subpoena to Flynn on May 31.

Jared Kushner, senior White House adviser

What you need to know about Jared Kushner's ties to Russia. (Thomas Johnson/The Washington Post)

What we know: On May 19, The Post's Devlin Barrett and Matt Zapotosky reported that a senior White House official was a focus of the FBI's Russia investigation — separate from the various investigations being run by Congress.

We knew Kushner had met with Kislyak and a Moscow banker in December, but U.S. intelligence officials are apparently concerned about the content of those meetings; Kushner reportedly asked Kislyak about the possibility of setting up a secret, secure communications channel with Moscow that would use Russian facilities. Flynn was also reportedly in that meeting.

What Kushner has turned over to investigators: “Mr. Kushner previously volunteered to share with Congress what he knows about these meetings. He will do the same if he is contacted in connection with any other inquiry,” Jamie Gorelick, one of Kushner's attorneys, told The Post.

Paul Manafort, former campaign manager

As a lobbyist and political consultant in the 1980s, Donald Trump's former campaign chairman Paul Manafort worked with international clients that included two dictators who were then allied with the United States. (Bastien Inzaurralde/The Washington Post)

What we know: Manafort, one of Trump's three campaign managers during the 2016 election, has had close ties to Russia for a long time. He was an adviser to Viktor Yanukovych, a Putin ally who was president of Ukraine from 2010 until he was ousted in 2014. He also has business connections with Russian oligarchs.

What Manafort has turned over to investigators: Manafort's lawyer told The Post that he is following through on a commitment to provide information to investigators. From reporter Tom Hamburger's story:

Congressional staff have not fully reviewed the new Manafort documents, but people familiar with them said they include calendar entries, speech drafts and campaign strategy memos that mention Russia or individuals from Russia. They also cite some specific meetings, including two large group sessions that involved Russia’s ambassador to the United States — one at the Republican National Convention and the other at the Mayflower Hotel in Washington when Trump gave his first major foreign policy address.

Roger Stone, former adviser

In an April interview with the Post, Roger Stone said he still talks with President Trump. (McKenna Ewen/The Washington Post)

What we know: Stone doesn't have direct, publicly known links to Russia, but during the campaign he suggested he may have insider information about potential WikiLeaks document dumps — which we know were facilitated by Russian intelligence operatives.

What Stone has turned over to investigators: As far as we know, he hasn't been contacted by investigators — but that doesn't mean he doesn't want to be.

“I myself am very anxious to testify before the House and Senate committees in public,” Stone said on CNN in March. “I don’t need a subpoena, I don’t need immunity — I’m going to give them whatever documents they requested, although I believe I’ve been under surveillance so they probably already have them anyway.”

Michael Caputo, former campaign communications adviser

What we know: Caputo lived in Russia in the 1990s and later worked with Russian conglomerate Gazprom Media on a pro-Putin public relations campaign. He worked for the Trump campaign as an adviser during the New York primary, but resigned after tweeting, “Ding dong the witch is dead!” after Trump campaign manager Corey Lewandowski was fired in June.

What Caputo has turned over to investigators: Congressional investigators reportedly asked Caputo for documents from his time as a Trump campaign aide in 2016. He reportedly complied.

“The only time the President and I talked about Russia was in 2013, when he simply asked me in passing what it was like to live there in the context of a dinner conversation,” Caputo reportedly told the House Intelligence Committee in a May letter.

Carter Page, former foreign policy adviser

The FBI obtained a secret court order to monitor communications from former Trump adviser Carter Page in summer 2016, according to law enforcement and intelligence officials. (Sarah Parnass/The Washington Post)

What we know: Page worked as an investment banker in Russia a decade ago. He also admitted to meeting with Kislyak in Cleveland during the Republican National Convention in July. The FBI obtained a special warrant to monitor him.

The Trump administration has disputed his role in the campaign, but Trump named Page as an adviser when he spoke with members of The Post's editorial board in March 2016.

What Page has turned over to investigators: Page, like Stone, has said on television that he's willing to testify to Congress, but hasn't yet.

Boris Epshteyn, former campaign adviser and assistant White House communications director

What we know: Epshteyn told the Associated Press on May 31 that he's been contacted by congressional committees and asked to turn over information. It's unclear whether he provided it.