A new filing from the special counsel Robert Mueller unsealed on Wednesday identifies two former journalists and the content of messages former Trump campaign chairman Paul Manafort and a Russian associate sent them in February, just two days after a superseding indictment against Manafort.

The 21-page document also names members of the so-called “Hapsburg group” – described by Mueller in the February superseding indictment of Manafort as "a group of former senior European politicians to take positions favorable to Ukraine, including by lobbying in the United States.”

According to the document, some of the key participants of the Hapsburg group are former Austrian Chancellor Alfred Gusenbauer, former Italian Prime Minister Romano Prodi, Belgian Judge Jean-Paul Moerman, head of the German Federal Chancellory Bodo Hombach and former Spanish NATO head Javier Solana.

The exhibit containing the names of Alan Friedman, Eckart Sager, Konstantin Kliminck, and Hapsburg group members, was filed by the clerk in an unredacted form on Wednesday afternoon but was re-filed a short time later in a redacted form with those names hidden.

Sager did not respond to ABC News' request for comment. Friedman was unable to be reached for comment

The existence of the text messages first came to light earlier this month, but the content of the messages was not publicly known until Wednesday’s filing. Last Thursday, Mueller, who is investigating Russian meddling during the 2016 election, cited the messages in accusing Manafort and his Russian associate, Konstantin Kliminck, of witness-tampering.

On Friday, Mueller filed a superseding indictment against Manafort that included Kliminck and new charges for obstruction of justice. Manafort faces two indictments in Washington, D.C., and Virginia on charges related to tax fraud and other financial crimes.

The special counsel has asked a federal judge in Washington, DC, to revoke Manafort's current $10 million bail. A hearing on Manafort’s bail is scheduled for this Friday.

Wednesday’s filing names Friedman and Sager – described in previous filings as Person D1 and Person D2 – as the recipients of Manafort and Kilimnik’s text messages.

According to those filings, on Feb. 26, Manafort sent a Business Insider article, in which it is reported that he had been charged with paying European leaders who were part of the Hapsburg group, to lobby on behalf of Ukraine to Friedman. He then wrote. “We should talk. I have made clear that they worked in Europe.”

In a series of messages sent in late February, Kilimnik asks Sager for assistance contacting Friedman.

“Basically P" - referring to Manafort - "wants to give him a quick summary that he says to everybody (which is true) that our friends never lobbied in the US, and the purpose of the program was EU,” Kilimnik wrote to Sager after asking him to mention the messages to Friedman. He then writes, “If you have a chance to mention this to A." - referring to Friedman - "it would be great. It would be good to get them connected to discuss in person. P is his friend.”

In April, Kilimnik reached out to Friedman directly in a message that said, “Hi. This is K. My friend P is looking for ways to connect to you to pass you several messages. Can we arrange that.”

Manafort’s trial in Virginia is slated to begin on July 25. His trial in Washington is scheduled for September 17.

Jack Date and Ali Dukakis contributed reporting.