Former Trump campaign chairman Paul Manafort lied about sharing polling data on the 2016 presidential race with Konstantin Kilimnik, an associate accused of having ties to Russian intelligence, according to a new court filing.
The information is in a redacted court filing from Manafort's lawyers but was visible to journalists because it was not properly blacked out.
According to the filing, prosecutors said Manafort lied to investigators about sharing the data with Mr Kilimnik.
Manafort allegedly shared the data while he was working on Donald Trump's Republican campaign.
Mr Kilimnik has denied ties to Russian intelligence.
Both men were indicted in special counsel Robert Mueller's investigation into Russian election interference and possible coordination with the Trump campaign.
Prosecutors said Manafort breached his plea deal by repeatedly lying to them.