Image copyright Reuters Image caption Paul Manafort resigned as chair of President Trump's election campaign after two months

Details of former Trump campaign chief Paul Manafort's alleged lies to investigators have been revealed in improperly redacted new court filings.

Special Counsel Robert Mueller's team accused him of lying about interactions with Konstantin Kilimnik, an alleged Russian operative, the papers say.

Manafort's lawyers argue in the filings he did not break his plea deal because he never meant to mislead anyone.

Mr Mueller is investigating alleged Russian meddling in the 2016 election.

In August, Manafort, 69, was convicted of financial fraud relating to his work as a political consultant in Ukraine, which pre-dated his role with Donald Trump's presidential campaign.

He accepted a plea deal on his other charges in exchange for co-operating with Mr Mueller's inquiry. The Mueller team accused him in November of breaking that deal by lying to investigators.

The redaction errors in Manafort's rebuttal show prosecutors believed he had lied about sharing 2016 polling data with Mr Kilimnik, as well as meeting him in Madrid and discussing Ukrainian politics while Manafort was managing the Trump campaign.

Manafort's lawyers have argued he provided truthful information to the best of his ability at the time.

The details about Manafort's alleged falsehoods come just as Russian lawyer Natalya Veselnitskaya, who famously attended a meeting with top Trump aides in 2016, was charged in a separate obstruction of justice case .

Additionally, the US Supreme Court on Tuesday ruled against a mystery foreign company for defying a grand jury subpoena related to the special counsel's inquiry.

Image copyright Reuters Image caption Manafort managed the Trump campaign for five months in 2016, during the time Mr Trump clinched his party's nomination

What did we learn from the documents?

The redaction mishap by Manafort's team allowed anyone to view the text beneath blacked out sections of the online documents when they became public on Tuesday.

In those sections, Manafort's lawyers say he "conceded" having possibly discussed a Ukraine peace plan with Mr Kilimnik on more than one occasion.

Manafort also "acknowledged" having met Mr Kilimnik "after being told" that the two were both in Madrid on the same day.

The lawyers said Ukraine-related matters "simply were not at the forefront of Mr Manafort's mind during the period at issue".

"It is not surprising at all that Mr Manafort was unable to recall specific details prior to having his recollection refreshed," Manafort's team wrote.

"The same is true with regard to the Government's allegation that Mr Manafort lied about sharing polling data with Mr Kilimnik related to the 2016 presidential campaign."

The documents also reveal that prosecutors accused Manafort of lying about his contact with administration officials after Mr Trump took office.

Manafort had previously said "he did not believe that he had any direct or indirect communications" with any officials while they served in the administration.

Mr Mueller's team said Manafort had had a conversation with an unnamed individual who wanted "to use Mr Manafort's name as an introduction" if they ever met President Trump, according to the filings.

Prosecutors also accused Manafort of telling a witness he "had contact" with another administration official.

Manafort's lawyers responded that any such conversation did "not constitute outreach by Mr Manafort to the President" and said the prosecution's second example was "hearsay".

Who is Konstantin Kilimnik?

Mr Kilimnik was considered Manafort's right-hand man in Ukraine and has been accused by the special counsel of conspiring to obstruct justice.

The Russian citizen was a long-time employee of Manafort's political consulting firm and had done extensive lobbying work for him in Ukraine on behalf of the country's then pro-Russian President, Viktor Yanukovych.

Mr Kilimnik has denied allegations that he has ties to Russian intelligence.

Video caption Donald Trump: "I feel very badly for Paul Manafort"

What's next?

Manafort will not ask for a hearing regarding the prosecution's accusations, according to the filings.

His lawyers reminded the court that Manafort had been co-operative and had no motive to lie, having voluntarily offered his electronic devices and communications to the government.

The ex-Trump aide had been hoping for leniency at his 5 March sentencing under the plea deal.

If he is found to have intentionally lied to the FBI, the government could seek a tougher sentence - including a maximum of life in prison.