A D.C. federal judge ruled Wednesday that Paul Manafort lied in three of five instances cited by special counsel Robert Mueller's office, invalidating his plea agreement with federal prosecutors, reports the Wall Street Journal.

US District Judge Amy Berman Jackson's ruling voids the government's obligation to offer him lenience in exchange for his cooperation in the Russia probe.

In particular, the judge ruled that Mr. Manafort lied about his communications with Konstantin Kilimnik, as well as payments to a law firm and another unspecified matter. The Federal Bureau of Investigation has assessed that Mr. Kilimnik, a Russian political operative who worked in Ukraine with Mr. Manafort and was also indicted by Mr. Mueller, has ties to Russian intelligence. Mr. Kilimnik remains at large. -Wall Street Journal

As a result of the ruling, Manafort won't receive any credit for his cooperation with prosecutors - and may serve out the rest of his natural life in jail on charges of tax evasion and unregistered lobbying.

Manafort was convicted last year in a similar Virginia trial, and pleaded guilty in the Washington case in the now-voided plea agreement designed to avoid another trial.

That said, Berman Jackson also ruled that federal prosecutors failed to prove that Manafort lied about Mr. Kilimnik's role in any potential conspiracy to obstruct justice, reports the Journal, and ruled that the government did not lie about his contacts with the Trump administration.

Prosecutors had contended that Mr. 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. -Wall Street Journal

"I’m not sure that is something that a prosecutor would prosecute as a criminal false statement necessarily," said Judge Berman Jackson, according to transcripts, apparently in reference to Kilimnik. Mueller prosecutor Andrew Weissmann told Berman Jackson that the issue went to the core of the special counsel's Russia probe.

Two months after Manafort's September plea agreement, prosecutors accused him of breaching it by lying several times over the course of his 12 or so sessions with investigators in front of the grand jury.

Manafort's attorneys denied that he intentionally lied to prosecutors - instead blaming his alleged misstatements on a poor memory and a lack of access to relevant documents and evidence, writes the Journal.

Manafort's case was related to his unregistered political consulting work for Ukraine's then-ruling party which predated his work with the Trump campaign.

He is scheduled to be sentenced in Washington on March 13, while the former Trump campaign manager is awaiting a sentencing date in Virginia where the judge postponed the hearing to see how the D.C. case was resolved.