Washington, Jun 5 (IANS): Special Counsel Robert Mueller has accused Paul Manafort, US President Donald Trump's former campaign chairman, of attempting to get witnesses to lie for him in court, according to a filing.

Manafort is currently out on house arrest and a $10 million unsecured bail, reports CNN.

He awaits a trial in Virginia that is scheduled for late July and a trial in Washington D.C. scheduled to begin in September.

He has pleaded not guilty to charges related to his failure to disclose his US lobbying work for a foreign government and to bank fraud and other financial crimes.

According to the filing in DC District Court on Monday night, one of the witnesses told investigators that Manafort wanted them to commit perjury about a lobbying effort they worked on for him in the US.

The new allegation places even more pressure on the former Trump campaign chairman, who has stared down prosecutors as they heaped charges on him and say they continue to investigate the possibility that he coordinated with Russians during the 2016 presidential election.

Monday's filing says that in late February, Manafort "repeatedly contacted" two anonymous people who may be witnesses against him, called Person D1 and D2.

Those two people had previously assisted lobbying and public relations efforts that Manafort masterminded in the US and Europe.

They have recently helped investigators find evidence of the witness tampering effort, prosecutors said.

Manafort's contacts with the two potential witnesses started benignly enough, with phone calls and text messages through the service WhatsApp, CNN quoted the filing as saying.

He currently wears two GPS monitor ankle bracelets on separate legs, keeping him confined to his Washington D.C. residence except for legal, medical and religious appointments.