A federal judge ruled that former Donald Trump campaign chairman Paul Manafort lied to investigators about his contact with an associate the FBI has linked to Russian intelligence despite agreeing to a plea deal requiring him to tell the truth, according to a Dow Jones Newswires report made available to EFE on Thursday.

United States District Judge Amy Berman Jackson said in a four-page order that the government met its burden of proof in showing that Manafort intentionally misled investigators on at least three matters. Her ruling voids the government's obligations under the agreement to offer him leniency in exchange for his cooperation in special counsel Robert Mueller's investigation of Russian interference in the 2016 election.

The ruling—which also said the government didn't persuade the court that Manafort lied on two other issues—is another blow to the long-time political consultant who earned tens of millions of dollars advising politicians in Ukraine.

It means that Manafort, who is already facing eight or more years in prison, potentially faces a longer punishment when he is sentenced next month.

In particular, the judge ruled that Manafort lied about his communications with Konstantin Kilimnik, as well as payments to a law firm, and that he made false statements relevant to another, unspecified Justice Department investigation.

At a sealed hearing last week, a prosecutor in Mueller's office described Manafort's contacts with Kilimnik as at "the heart" of what the special counsel is investigating, noting the Federal Bureau of Investigation's assessment that Kilimnik had a "relationship with Russian intelligence."

Mueller's office previously charged Kilimnik with helping Manafort try to influence potential witnesses in the investigation. Kilimnik remains at large.

It wasn't clear whether the full investigation into communications between Kilimnik and Manafort could move forward without Manafort's cooperation.

The decision does mean that Manafort won't receive any credit for his cooperation with prosecutors.

Manafort was convicted of tax and bank fraud in a Virginia trial last year and pleaded guilty in Washington soon after to additional, related charges.

In her Wednesday order, Judge Berman Jackson also ruled the government had failed to prove that Manafort lied about Kilimnik's role in any potential conspiracy to obstruct justice. She also ruled that the government didn't prove that Manafort lied about his contacts with the Trump administration.

Prosecutors had contended that Manafort had repeatedly told "multiple discernible lies" just weeks after he pleaded guilty and agreed to cooperate in the Mueller investigation.

In a closed-door hearing last week, Judge Berman Jackson had questions for prosecutors over their allegations.

"I'm not sure that is something that a prosecutor would prosecute as a criminal false statement necessarily," Judge Berman Jackson said at that hearing, referring to one of the allegations, according to heavily redacted transcripts.

Prosecutor Andrew Weissmann told the judge that several of Manafort's alleged lies involved issues core to the special prosecutor's inquiry into Russian interference in the 2016 election and any links to the Trump campaign.

He also said Manafort had motives to mislead investigators and deliberately conceal information.

Manafort was one of the few targets of Mueller's investigation to fight charges in court, but that effort has been largely unsuccessful.

Just two months after he reached his September plea agreement, prosecutors accused Manafort of breaching his plea deal and said he had lied many times over the course of his dozen sessions with investigators and before the grand jury.

Manafort's attorneys have denied that he intentionally lied to prosecutors. Instead they have blamed his alleged misstatements on a faulty memory and his lack of access to relevant documents and evidence before his multiple meetings with prosecutors.

The case against Manafort was related to his political consulting work in Ukraine for pro-Russian politicians that predated his work with the Trump campaign.

In responding to the allegations, Manafort's attorneys also inadvertently disclosed last month that Manafort gave 2016 polling data to Kilimnik, and may have discussed a peace plan for Ukraine with him.

At the hearing, prosecutors also discussed a poll in Ukraine that Manafort assisted on and about which he allegedly misled investigators.

Manafort is scheduled to be sentenced in Washington on March 13.

He was also awaiting a sentencing date in Virginia, where the judge postponed the hearing to see how the breach of the plea-deal issue was resolved.

By Byron Tau and Aruna Viswanatha