President Donald Trump's ex-lawyer has given substantial help on how Russian nationals tried to affect the 2016 election, a legal memo has revealed.
Michael Cohen's help is detailed in the memo from Robert Mueller, who is heading the probe into alleged Russian collusion with the Trump team.
The memo is mainly to guide sentencing for crimes Cohen has admitted.
A second Mueller memo sets out the case against ex-campaign chief Paul Manafort for breaching a plea bargain deal.
Cohen and Manafort are among a number of Trump aides being investigated in Special Counsel Mueller's probe.
Both have been co-operating with his team but Mr Mueller now accuses Manafort of lying.
In a separate court filing on Friday, prosecutors in New York made their case for the length of Cohen's sentence when it is delivered on Wednesday.
They say he should serve a "substantial" jail term after admitting violating campaign finance laws, committing tax evasion and lying to Congress.
President Trump has repeatedly denied there was any collusion with Russian officials, calling the investigation a "witch hunt".
The White House said Friday's memos offered nothing new or damaging about the president.
The memo says that although this crime was serious, any sentencing should be served concurrently with the New York prosecutors' recommendations on other crimes.
The memo says Cohen has taken "significant steps to mitigate his criminal conduct".
The key elements of the memo are about the Russian links. They are that Cohen:
"Provided information about his own contacts with Russian interests during the campaign and discussions with others in the course of making those contacts"
"Also provided information about attempts by other Russian nationals to reach the campaign"
Spoke to "a Russian national who claimed to be a 'trusted person' in the Russian Federation who could offer the campaign 'political synergy' and 'synergy on a government level'". This person proposed a meeting between Individual 1 (previously identified by Cohen as Mr Trump) and the Russian president, saying it could have a "phenomenal" impact "not only in political but in a business dimension as well". The meeting did not take place
Provided "relevant and useful information concerning his contacts with persons connected to the White House during the 2017-2018 time period
The Manafort memo
Paul Manafort served for five months with the Trump campaign team, three of them as campaign manager, before being sacked.
This latest memo, from Mr Mueller's office, tries to spell out how the special counsel believes Manafort breached a plea bargain deal by lying to investigators.
The memo lists five allegations of breaching the deal by lying:
On his interaction with Konstantin Kilimnik, a business associate who Mr Mueller says is
tied to Russian intelligence. The actual allegations in the memo are redacted
A second case involving Kilimnik and obstruction of justice
Payment to a firm working for Manafort
On a separate department of justice inquiry
On contacts with Trump administration officials
The memo calls these "multiple discernible lies - these were not instances of mere memory lapse".