Michael Cohen's lawyers revealed intriguing new details about President Donald Trump in a new court filing this week.

Cohen pleaded guilty to lying to Congress and is cooperating with the special counsel Robert Mueller.

Cohen's lawyers say he was "in close and regular contact" with Trump's lawyers and White House staffers in the weeks before he lied to lawmakers.

They also revealed that Cohen is cooperating with a mysterious "separate open inquiry" conducted by the New York attorney general's office.

When he was breaking campaign-finance laws at Trump's direction, Cohen's lawyers say he kept Trump "contemporaneously informed" of his actions.

In a sentencing memorandum submitted this week, Michael Cohen's lawyers said he was "in close and regular contact" with President Donald Trump's lawyers and White House staff in the weeks leading up to his congressional testimony last year.

The detail was just one of several bombshell revelations Cohen's lawyers made in the memorandum, which they submitted after Cohen pleaded guilty to one count of lying to Congress and formally began cooperating with the special counsel Robert Mueller this week.

Prosecutors said in a charging document that Cohen misled congressional investigators last year about the Trump Organization's effort to build a Trump Tower in Moscow during the 2016 US presidential election.

They said Cohen lied when he said negotiations for the Trump Tower Moscow deal ended in January 2016 and that he did not discuss it extensively with Trump Organization executives. They added that Cohen gave false testimony "in hopes of limiting the ongoing Russia investigations."

Michael Cohen and Donald Trump. Jonathan Ernst/Reuters

Cohen was in regular contact with Trump's lawyers and the White House before he lied to Congress

In their sentencing memorandum, Cohen's lawyers said his false statements to Congress stemmed from his effort, "as a loyal ally and then-champion of Client-1, to support and advance Client-1's political messaging." Client-1 is believed to be Trump.

Cohen was the Trump Organization's lead attorney for a decade, until he left in 2017 to be Trump's personal lawyer. He was serving in that capacity when he was asked to appear before the House and Senate intelligence committees last year to testify in each panel's respective Russia investigation.

At the time, Cohen "followed daily the political messages that both Client-1 and his staff and supporters repeatedly and forcefully broadcast," his lawyers wrote. "Furthermore, in the weeks during which his then-counsel prepared his written response to the Congressional Committees, Michael remained in close and regular contact with White House-based staff and legal counsel to Client-1."

The president and his supporters have decried the Russia investigation as a politically motivated "witch hunt" since its existence first became public knowledge last March. And while the White House initially applauded Mueller's appointment as special counsel last May, Trump quickly switched gears and accused Mueller and the FBI, without evidence, of catering to Democrats and having anti-Trump bias.

Robert Mueller. Chip Somodevilla/Getty Images

Cohen's lawyers wrote that based on Trump's political messaging and Cohen's regular contact with Trump's lawyers and White House staff, he was "fully aware of Client-1's repeated disavowals of commercial and political ties between himself and Russia, as well as the strongly voiced mantra of Client-1's that investigations of such ties were politically motivated and without evidentiary support."

They added that Cohen was also aware of Trump's specific "aim to dismiss and minimize the merit" of the Russia probe, as well as Trump's and his representatives' claim that all contacts with Russians by Trump, his campaign, or the Trump Organization had ended before the Iowa caucuses, which took place on February 1, 2016.

Cohen's lawyers wrote that in accordance with that knowledge, Cohen misrepresented the timeline of the Trump Tower Moscow deal to Congress and downplayed the extent of his communications with Trump about the deal. They added elsewhere in the memo that Cohen's false statements "arose from Michael’s fierce loyalty to Client-1" and that his "conduct was intended to benefit Client-1, in accordance with Client-1’s directives."

Cohen has cooperated with a mysterious 'separate open inquiry'

In August, Cohen pleaded guilty to charges related to tax evasion, bank fraud, and campaign-finance violations. The charges were part of a separate investigation, by prosecutors from the Southern District of New York, into Cohen's and Trump's financial dealings leading up to the 2016 election.

Cohen's lawyers wrote in the sentencing memorandum that he has voluntarily met twice with prosecutors in the Manhattan US attorney's office. He has also participated in seven voluntary meetings with Mueller's team and given over 70 hours of interviews to the special counsel. His first meeting with Mueller's office came shortly before Cohen pleaded guilty in the Manhattan US attorney's office investigation.

His most recent sit-down with Mueller was last week.

Cohen's lawyers added in the memorandum that he has also voluntarily met with representatives from the New York attorney general's office, which is currently investigating the Donald J. Trump Foundation, Trump, and his children.

The lawsuit, which was filed in June against Trump, Donald Trump Jr., Ivanka Trump, Eric Trump, and the Trump Foundation, alleges "a pattern of persistent illegal conduct" for more than a decade.

Cohen's lawyers included another intriguing detail in their memo: in addition to cooperating with the investigation into the Trump Foundation, Cohen has also "provided the [New York attorney general's office] with documents concerning a separate open inquiry."

They did not elaborate on what that inquiry is.

Win McNamee/Getty Images

When he was breaking campaign-finance laws at Trump's direction, Cohen kept Trump 'contemporaneously informed' of his actions

When Cohen pleaded guilty to campaign-finance violations in August, he told prosecutors he acted at Trump's direction.

The charges stem from payments made shortly before the election to two women who claim to have had affairs with Trump, in exchange for their silence. Trump and his lawyers have repeatedly denied knowing anything about the payments and maintain that he did nothing wrong.

But in their sentencing memorandum, Cohen's lawyers wrote that Cohen kept Trump "contemporaneously informed and acted on [his] instructions" when it came to both the payments.

"Michael felt obligated to assist Client-1, on Client-1’s instruction, to attempt to prevent Woman-1 and Woman-2 from disseminating narratives that would adversely affect the Campaign and cause personal embarrassment to Client-1 and his family," Cohen's lawyers added.

Cohen broke campaign-finance laws for the same reason he lied to Congress, his lawyers said. "Both arose from Michael's fierce loyalty to Client-1. In each case, the conduct was intended to benefit Client-1, in accordance with Client-1's directives."

Cohen's lawyers said he is seeking an early sentencing date so he can begin rebuilding his life and look for new means to support his family. But they added that "this personal decision does not signal any intention on Michael's part to withhold information or his availability to respond to additional inquiry."

"To the contrary," they said, "he expects to cooperate further."