The Post and other media were careful to note that their sources did not say Kushner was a "target" of the investigation, nor that he was accused of any wrongdoing.
US President Donald Trump's son-in-law and senior adviser Jared Kushner spoke with Russias ambassador about establishing a secret communications channel between the Trump transition team and Moscow, said US officials briefed on intelligence reports.
Kushner is under investigation for the "extent and nature" of his interaction with Russian officials, The Washington Post reported.
The White House did not immediately comment on the Post's Friday report.
But H.R. McMaster, who replaced Mr Flynn as National Security Adviser said so-called "back-channeling" was completely normal. After Trump took office, Flynn was forced to resign from the administration because of revelations that he had misrepresented his conversations with Kislyak to Vice President Pence.
"The White House disclosed the fact of the meeting only in March, playing down its significance".
The Times reported that Flynn was at the center of the idea.
Two other outlets published related scoops yesterday.
"We have backchannel communications with a number of countries", McMaster said.
Miller reports that even Russians were concerned about the security risks of such an arrangement.
Flynn served briefly as Trump's national security adviser before being fired in February after officials said he misled Vice President Mike Pence about whether he and the ambassador had discussed US sanctions against Russian Federation in a phone call. "So bringing an American in to use that phone line would be pretty remarkable".
"It's easy to see why the Federal Bureau of Investigation would be intrigued by this", Miller says.
White House officials kept mum on Saturday about the controversy swirling around President Trump's senior adviser and son-in-law Jared Kushner.
"It should be clear to everyone Russian Federation brazenly interfered in our 2016 presidential election process and that they undertook these activities despite our strong protests and explicit warning that they do not do so", he told the US House of Representatives Intelligence Committee.
The FBI, in the course of its investigation into Russian involvement in the 2016 election, is now also looking at Kushner's multiple roles in Trump's campaign operation and his contacts with Russian officials. Since the firing of FBI Director James Comey, a special counsel has been tapped to lead the FBI probe, and the various congressional committees are continuing their work.
The newspaper cited anonymous USA officials who were briefed on intelligence reports on intercepted Russian communications.
A man of few words who is never far from the president's side, Kushner boasts an enormous portfolio of domestic and global responsibilities, underscoring his importance as Trump's chief aide-de-camp, despite having no experience in the world of politics before the 2016 race.
The revelation, if confirmed, would raise new questions about the Trump team's relationship with the Russians, who United States intelligence agencies say tried to sway the November election in Trump's favor.
"The president, when I left to get here, was still in the G-7 meeting with the heads of state", Cohn said.
"Hard to fully convey the gravity of this", said Susan Hennessey, a national security fellow at the Brookings Institution and a former lawyer for the National Security Agency, of the Washington Post report. The White House has denied that Trump asked Comey to end the FBI's inquiry regarding Flynn. In addition to expelling 35 diplomats, and sanctioning 9 individuals/entities, the President also announced the closure of two Russian diplomatic compounds in the US.
The latest bombshell ensures that Trump will be thrust right back into the Russian Federation scandal upon his return to Washington this weekend, after making his global debut with a tour of the Middle East and Europe. "I'm not talking about campaigns".