National Security Advisor Michael Flynn's communications with Russian officials have been investigated by U.S. counterintelligence agents.
The Wall Street Journal reported the inquiry just hours after Flynn was sworn in Sunday as Donald Trump's assistant to the president for national security affairs.
It's not clear when the investigation into Flynn's communications began or whether it turned up any incriminating evidence, and the newspaper was unable to confirm whether the probe was still ongoing.
Investigators focused primarily on Flynn's communications with Sergey Kislyak, the Russian ambassador to the U.S., on Dec. 29 -- the day the Obama administration announced sanctions against Russia.
The newspaper reported that investigators were trying to determine whether Flynn's contact with Russian officials violated any laws, citing sources familiar with the probe.
The White House denied the investigation Sunday.
The New York Times reported Thursday has identified three Donald Trump associates — Paul Manafort, Carter Page and Roger Stone — whose ties to Russia are under investigation by U.S. law enforcement agencies.
