Washington • Special counsel Robert Mueller obtained court-approved warrants to search the emails of President Donald Trump’s lawyer Michael Cohen in July 2017, according to newly unsealed documents illustrating how the investigation moved quickly and quietly to scour the digital trails of the president’s associates.

Search warrants unsealed Tuesday in Cohen’s case offer new insight into how Mueller and his team handed off a key part of the Cohen investigation to federal prosecutors in New York in early 2018, and how much evidence prosecutors already had against Cohen even before they searched his office, home, and hotel room in April of that year.

"In connection with an investigation then being conducted by the Office of the Special Counsel ("SCO"), the FBI sought and obtained from the Honorable Beryl Howell, Chief United States District Judge for the District of Columbia, three search warrants for emails and other content information associated with two email accounts used by Cohen, and one search warrant for stored content associated with an iCloud account used by Cohen," states one of the newly-unsealed affidavits.

The first such warrant was dated July 18, 2017. In early 2018 the special counsel's office referred a part of its Cohen investigation to federal prosecutors in New York. As part of that referral, on Feb. 8, 2018, the special counsel's office turned over relevant emails from its warrants to the New York prosecutors, according to one of the newly-unsealed affidavits.​

Cohen's home, office, and hotel room were searched nearly a year ago as the FBI ratcheted up its investigation of the lawyer's finances, and his work on behalf of Trump. That same day agents also executed a search warrant for a safe-deposit box used by Cohen.

The searches set off a protracted legal battle over how the files of Cohen, an attorney, would be reviewed by agents and prosecutors. A federal judge appointed an outside lawyer to review the material before Cohen's prosecutors to exclude any material that was covered by lawyer-client privilege or otherwise should not be shared with investigators.

Months later, Cohen pleaded guilty to tax violations, lying to a bank, and, during the 2016 campaign, arranging hush-money payments for women who claimed that they once had affairs with the future president.

Cohen also pleaded guilty to lying to Congress in statements that concealed the true time frame in which he had sought a real estate development deal for a Trump Tower in Moscow - conversations that continued, contrary to initial claims, well into the Republican presidential primary.

At Cohen’s December sentencing, U.S. District Judge William Pauley III said Cohen should serve three years in prison for “a veritable smorgasbord of criminal conduct.”

Cohen cooperated — partially — with federal prosecutors in New York, as well as special counsel Robert Mueller, in hopes of reducing the amount of prison time he would have to serve.

Cohen has provided information to investigators about Trump and the Trump campaign, but prosecutors said he refused to tell them everything he knew.

Since pleading guilty, he has publicly blamed Trump for his downfall, calling his former boss a con man, a racist, and a cheat. Trump and his supporters have repeatedly attacked Cohen as a convicted liar trying to save himself by speaking against his former boss.

In dramatic public testimony to a congressional committee last month, Cohen declared, "I am no longer your fixer, Mr. Trump."

Cohen is due to report to prison in May, and he is likely to serve his sentence at a federal lockup in Otisville, New York.