US prosecutors say Paul Manafort, President Donald Trump’s former campaign chairman, has breached a plea bargain agreement by lying to the FBI.
The special counsel investigating alleged Russian meddling in the US election said the breach meant there was now no reason to delay sentencing.
In August, Manafort was convicted of financial fraud relating to his work as a political consultant in Ukraine.
Manafort’s lawyers say they believe he provided truthful information.
A month later he pleaded guilty to two other criminal charges in a plea deal with Special Counsel Robert Mueller.
It was the first criminal trial arising from the justice department’s investigation into alleged interference by Russia in the 2016 election.
The White House has insisted that the guilty plea had absolutely nothing to do with President Trump.
What has Robert Mueller said?
In September Manafort accepted the plea deal on related conspiracy charges in return for an agreement to co-operate with Mr Mueller’s investigation.
But in a court filing on Monday, Mr Mueller said that after signing the deal “Manafort committed federal crimes by lying to the Federal Bureau of Investigation and the Special Counsel’s office on a variety of subject matters”.
It did not give details of what Manafort allegedly lied about.
In the same filing, Manafort’s legal team said their client had “provided information to the government in an effort to live up to his co-operation obligations”.
“He believes he has provided truthful information and does not agree with the government’s characterisation or that he has breached the agreement,” his lawyers said.
Manafort has been held in a detention centre in Virginia since June.
What charges has Manafort faced?
In August he was convicted on eight counts of fraud, bank fraud and failing to disclose bank accounts.
A month later he pleaded guilty to one charge of conspiracy against the US and one charge of conspiracy to obstruct justice in the plea bargain with Mr Mueller. The agreement avoided a second trial on money laundering and other charges.
The charges only relate to Manafort’s political consulting with pro-Russian politicians in Ukraine, largely pre-dating his role with the Trump campaign.
He faced up to 10 years in prison under the deal and will also forfeit four of his properties and the contents of several bank accounts.
Deadlocked charges from the previous trial were to be dismissed if there was “successful co-operation” with the special counsel. It is not clear if these charges will now be refiled.
How did we get here?
Manafort, 69, worked for the Trump presidential campaign for five months in 2016 and was in charge when Mr Trump clinched the Republican party nomination.
President Trump has branded the Mueller investigation a “witch hunt” and insisted there was no collusion between his team and Russia. The Kremlin has also repeatedly denied any meddling.
Manafort was charged by Mr Mueller last October and at trial he was accused of using 31 foreign bank accounts in three different countries to evade taxes on millions of dollars.
Prosecutors presented evidence of Manafort’s luxurious lifestyle, saying it was only possible because of his bank and tax fraud.
Following his conviction, President Trump praised his former campaign chairman for refusing to “break” under legal pressure.