An accidentally unredacted court filing shows former Trump campaign chairman Paul Manafort gave polling data to a Ukrainian associate with Russian military intelligence ties, and Mueller most likely gained that information through a program run by the National Security Agency, according to former NSA analyst John Schindler.
"Did you know Paul Manafort was sharing polling data from your campaign with the Russians?" Trump responded, "No. I didn't know anything about that".
The revelation came this week in court documents filed by Manafort's defense lawyers that accidentally included details that were meant to be redacted.
Legal experts told ABC News this week that sharing campaign polling data with a foreign person is not a crime, but could be an important piece to the puzzle concerning possible Trump campaign coordination with Russians during the 2016 campaign - a subject being investigated by special counsel Robert Mueller's office.
President Donald Trump has denied all allegations that his campaign colluded with the Russian government to subvert the 2016 presidential election, and denied knowing about any contact between Manafort and Kilimnik when approached by reporters on the White House's South Lawn.
Mueller has seized Manafort's electronic communication records, and Schindler says the special counsel learned about his early 2017 trip to Madrid through the travel tracking program revealed by former NSA contractor Edward Snowden.
But that plea deal fell apart after prosecutors accused him of lying.
Fabrizio had a previous relationship with Manafort prior to his work on Trump's campaign, CNN reported.