By Zachary Cohen

CNN

WASHINGTON (CNN) -- After months of dramatic congressional testimony, bombshell news reports and partisan jousting, the ever-evolving saga about alleged Russian tampering in the 2016 presidential election and investigation into possible collusion by members of Donald Trump's campaign continues to pick up momentum as new revelations seem to surface on a daily basis.

Currently, the Justice Department and both chambers of Congress are investigating whether there were improper contacts between those in the Trump orbit and Russia during the 2016 election.

Here is a summary of known connections between Trump associates and Russia.

The latest development comes as sources tell CNN that Russian government officials discussed having potentially "derogatory" information about then-presidential candidate Trump and some of his top aides in conversations intercepted by US intelligence during the 2016 election.

One source described the information as financial in nature and said the discussion centered on whether the Russians had leverage over Trump's inner circle. The source said the intercepted communications suggested to US intelligence that Russians believed "they had the ability to influence the administration through the derogatory information."

But the sources, privy to the descriptions of the communications written by US intelligence, cautioned the Russian claims to one another "could have been exaggerated or even made up" as part of a disinformation campaign that the Russians did during the election.

Sources have also told CNN that then-FBI Director James Comey knew that a critical piece of information relating to the investigation into Hillary Clinton's email was fake -- created by Russian intelligence -- but he feared that if it became public it would undermine the probe and the Justice Department itself.

As a result, Comey acted unilaterally last summer to publicly declare the investigation over -- without consulting then-Attorney General Loretta Lynch -- while at the same time stating that Clinton had been "extremely careless" in her handling of classified information. His press conference caused a firestorm of controversy and drew criticism from both Democrats and Republicans.

Comey's actions based on what he knew was Russian disinformation offer a stark example of the way Russian interference impacted the decisions of the highest-level US officials during the 2016 campaign.

CNN has also learned that the FBI's criminal probe is increasingly touching on the multiple roles of senior White House adviser Jared Kushner on both the Trump campaign and the Trump transition team.

Points of focus that pertain to Kushner include: the Trump campaign's 2016 data analytics operation; his relationship with former national security adviser Michael Flynn; and Kushner's own contacts with Russians, according to US officials briefed on the probe.

That news came on the heels of CNN's reporting that Attorney General Jeff Sessions did not disclose meetings he had last year with Russian officials when he applied for his security clearance, according to the Justice Department.

Sessions, who met with Russian Ambassador Sergey Kislyak at least two times last year, didn't note those interactions on the form, which requires him to list "any contact" he or his family had with a foreign government or its representatives over the past seven years, officials said.

To obtain a security clearance, a federal official is not required to list the meetings if they were part of a foreign conference he or she attended while conducting government business. Sessions' meetings, however, do not appear to be tied to foreign conferences.

Sessions is just the latest in a growing list of current and former Trump associates who have come under fire for being less than forthcoming about their past links to Russia.

Trump's former national security adviser Michael Flynn continues to make headlines despite saying he would invoke his Fifth Amendment rights rather than comply with a subpoena and disclose records about his meetings with Russian officials.

The leaders of the Senate's Russia investigation said they will continue to pursue critical documents from Flynn, issuing two additional subpoenas to a pair of businesses Flynn ran.

Previously, lawmakers have said the panel was reviewing a range of options to compel Flynn hand over the documents, including holding him in contempt. Committee chairman Sen. Richard Burr said the panel "could" call for Flynn to assert his right against self-incrimination in a public session.

People to know

See CNN's list of the growing and diverse cast of characters who have played a role in this story.

How we got here

Here is a timeline with everything you need to know about the key players in the Russia-White House story and their roles in some of the most pivotal moments so far.

The firing of now-former FBI director James Comey was one of the most high-profile moments. Here is how it played out.

The latest

Secret document: The Washington Post published a story May 24 claiming that a secret document that officials said played a key role in then-FBI director Comey's handling of the Hillary Clinton email investigation "has long been viewed within the FBI as unreliable and possibly a fake." The Post's story sites anonymous sources "familiar with its contents."

Explosive testimony: Former CIA Director John Brennan and Trump's Director of National Intelligence Dan Coats also made headlines as Brennan told lawmakers there was clear contact between Trump campaign aides and Russian operatives.

At almost the same time, Coats said he would be willing to discuss later whether Trump leaned on him to push back against Russia reports. Here is more on what we learned from their congressional testimony May 23.

Mueller and the secret Comey memos: CNN broke the story May 22 that Robert Mueller -- the former FBI director now overseeing the Department of Justice's investigation into Russia's election-year meddling and contact with the Trump campaign -- has been briefed on the contents of some of the memos that former FBI Director James Comey kept to document his conversations with Trump, according to a person familiar with the matter.

Team Trump's "war room": Axios recently reported that the White House is preparing to establish an internal, war-room-like operation aimed at developing a rapid-response and communications strategy in an attempt to keep up with the special counsel's Russia investigation.

Manafort turns over documents: Paul Manafort, Trump's former campaign manager, turned over more than 300 pages of documents to the Senate intelligence committee related to its investigation of Russian election meddling, according to a source familiar with the Senate probe. Read CNN's story here.

Trump asked intelligence officials to deny evidence: The President asked two of the government's top intelligence chiefs to publicly deny evidence of cooperation between his campaign and Russia during the 2016 election, multiple current and former US officials confirmed to CNN on May 23. Read the full story.

CNN's Russia coverage

CNN has delivered reporting and analysis on some of the key moments throughout the Trump-Russia saga. Here is a look back at some of the developments to date.

January 10, 2017: Intel chiefs presented Trump with claims of Russian efforts to compromise him -- Classified documents presented to President Barack Obama and President-elect Trump included allegations that Russian operatives claim to have compromising personal and financial information about Trump, multiple US officials with direct knowledge of the briefings told CNN. Read more.

February 10, 2017: US investigators corroborate some aspects of the Russia dossier -- US investigators said they corroborated some of the communications with foreign nationals detailed in a 35-page dossier compiled by a former British intelligence agent, multiple current and former US law enforcement and intelligence officials told CNN. As CNN first reported, then-President-elect Trump and Obama were briefed on the existence of the dossier before Trump's inauguration. Full story here.

February 14, 2017: Trump aides were in constant touch with senior Russian officials during campaign -- High-level advisers close to then-presidential nominee Trump were in constant communication during the campaign with Russians known to US intelligence, multiple current and former intelligence, law enforcement and administration officials told CNN. Read more.

February 24, 2017: FBI refused White House request to knock down recent Trump-Russia stories -- The FBI rejected a recent White House request to publicly knock down media reports about communications between Trump's associates and Russians known to US intelligence during the 2016 presidential campaign, multiple US officials briefed on the matter told CNN. Read more.

March 23, 2017: Info suggests Trump associates may have coordinated with Russians, US officials say -- The FBI has information that indicates Trump associates communicated with suspected Russian operatives to possibly coordinate the release of information damaging to Hillary Clinton's campaign, US officials told CNN. Full story here.

April 18, 2017: FBI used dossier allegations to bolster Trump-Russia investigation -- The FBI last year used a dossier of allegations of Russian ties to Trump's campaign as part of the justification to win approval to secretly monitor a Trump associate, according to US officials briefed on the investigation. Full story.

April 21, 2017: Sources: Russia tried to use Trump advisers to infiltrate campaign -- The FBI gathered intelligence last summer that suggests Russian operatives tried to use Trump advisers, including Carter Page, to infiltrate Trump's campaign, according to US officials. These officials made clear they don't know whether Page was aware the Russians may have been using him. Full story.

May 10, 2017: Grand jury subpoenas issued in FBI's Russia investigation -- Federal prosecutors issued grand jury subpoenas to associates of former national security adviser Michael Flynn seeking business records as part of the probe of Russian meddling in last year's election, according to people familiar with the matter. CNN learned of the subpoenas hours before Trump fired then-FBI director Comey. Read more.

May 19, 2017: Sources: White House lawyers research impeachment -- White House lawyers have begun researching impeachment procedures in an effort to prepare for what officials still believe is a distant possibility that Trump could have to fend off attempts to remove him from office, two people briefed on the discussions told CNN. Full story here.

May 19, 2017: Russian officials bragged they could use Flynn -- Russian officials bragged in conversations during the presidential campaign that they had cultivated a strong relationship with former Trump adviser Flynn and believed they could use him to influence Trump and his team, sources told CNN. Read more.

May 19, 2017: Comey believes Trump was trying to influence him -- The former FBI director now believes that Trump was trying to influence his judgment about the Russia probe, a person familiar with his thinking said, but whether that influence amounts to obstruction of justice remains an open question. Full story.

May 24, 2017: AG Sessions did not disclose Russia meetings in security clearance form, DOJ says -- Attorney General Sessions did not disclose meetings he had last year with Russian officials when he applied for his security clearance, the Justice Department told CNN. Read it here.

May 30, 2017: Sources: Russians discussed potentially 'derogatory' information about Trump and associates during campaign -- Russian government officials discussed having potentially "derogatory" information about then-presidential candidate Trump and some of his top aides in conversations intercepted by US intelligence during the 2016 election, according to two former intelligence officials and a congressional source. Read more.

CNN's Marshall Cohen contributed to this report.