U.S. President Donald Trump's former campaign manager, Paul Manafort, who has been indicted by special counsel Robert Mueller, attempted to tamper with potential witnesses, Mueller said in a court filing on Monday.
After Manafort's charges were adjusted in DC federal court related to his lobbying work in late February - on the same day Rick Gates pleaded guilty to lying to investigators about the group - Manafort called one of the people's cell phones and texted the person encrypted messages, prosecutors say.
Prosecutors said Mr Manafort has broken violations of his release while he awaits trial.
They asked a federal judge to revise the terms of his release or revoke it entirely, which would send him to jail until trial. They also said an associate of Manafort's tried to contact a potential witness a few times. I think, however, they were doing a number on Trump himself.
The two witnesses are not named in court filings. But prosecutors say they worked with Manafort in organising a group of former European officials, known as the Hapsburg Group, who promoted Ukrainian interests in Europe as well as the US.
Manafort faces multiple felony charges in two federal cases, including conspiracy against the United States, conspiracy to launder money, failing to register as an agent of a foreign principal, giving false and misleading Foreign Agents Registration Act statements and providing other false statements.