A new court filing says that US President Donald Trump's former campaign chairman Paul Manafort lied about sharing polling data on the 2016 presidential race with Konstantin Kilimnik, an associate accused of having ties to Russian intelligence.

The information is in a redacted court filing, unsealed on Tuesday, from Manafort's lawyers. The Associated Press was able to view the redacted material because it wasn't properly blacked out.

According to the filing, prosecutors say Manafort lied to investigators about sharing the data with Kilimnik. Manafort allegedly shared the data while he was working on Donald Trump's Republican campaign.

Kilimnik has denied ties to Russian intelligence.

Both men were indicted in Special Counsel Robert Mueller's investigation into Russian election interference and possible coordination with the Trump campaign. Trump has maintained there has been "no collusion".

The filing also said that any "misstatements" made by Manafort, to federal prosecutors were "unintentional" and he would not seek a hearing to contest the allegation he lied.

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Manafort was responding to allegations in December by Mueller that Manafort had told "multiple discernible lies" to investigators, breaking a plea agreement struck in September.

Manafort's lawyers had been given until Monday to decide whether they would challenge the allegations, a move that would require a court hearing to weigh evidence, or simply ask the government to move on to sentencing. The filing was submitted under seal on Monday, and the redacted version released on Tuesday.

The former Trump campaign chief's lawyers said their client has been suffering from gout, anxiety and depression and that he never purposely lied to them during his 12 interview sessions with the special counsel and other prosecutors.

"The defence contests the Government’s conclusion and contends that any alleged misstatements, to the extent they occurred at all, were not intentional," Manafort's lawyers said in the filing to US District Judge Amy Berman Jackson in Washington, who is handling one of two cases against Manafort.

'Lied about at least five subjects'

When Manafort pleaded guilty in September in Berman Jackson's court, he promised to cooperate fully with Mueller's office and other Justice Department probes in return for a recommendation of leniency at sentencing.

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But Mueller's office said Manafort had lied about at least five subjects, including his interactions with Kilimnik.

Manafort, who earned millions of dollars for his political consulting work for Ukraine's former pro-Russia government, has emerged as a key figure in Mueller's investigation.

In addition to his ties to Kilimnik, Manafort had for years worked for Oleg Deripaska, a Russian oligarch who was sanctioned by the US Treasury in April for allegedly supporting the Kremlin's "malign activity" around the world.

Manafort, 69, was convicted in August in a separate case in Virginia, for evading taxes on $16m earned as a political consultant in Ukraine and lying to banks to get loans. He is due to be sentenced in that case next month.

Russia has denied meddling in the election. Trump has said there was no collusion between his campaign and Moscow.