The special counsel received warrants nearly a year before the raid to begin reading Cohen’s private email correspondence, according to court documents that were unsealed on Tuesday morning and reviewed by The Independent.

Initially, the special counsel's office had launched a probe into whether Cohen was acting as an unregistered foreign agent, an allegation he has not been charged over.

When federal prosecutors raided Cohen’s properties in April of last year, they seized all sorts of material evidence as part of their investigation into Donald Trump’s 2016 presidential campaign and Russian interference in the general election.

According to exhibit 6 of the partially redacted records, prosecutors seized at least two DVDs and a USB flash drive. It remained unclear what significance any of this evidence has played in the special counsel probes.

However, one of the DVDs in question featured a date prominently displayed on a label reading “Cohen – 2018.03.07.” That date – 7 March, 2018 – was the same day numerous outlets reported on a secret restraining order Cohen had sought against Stormy Daniels, an adult film star who has alleged to have had an extramarital affair with Mr Trump. Another DVD featured a label reading “2-28-18 Cohen SW Returns – Google and 1&1.”

Criminals who worked for Trump Show all 5 1 /5 Criminals who worked for Trump Criminals who worked for Trump Michael Cohen Former lawyer for Donald Trump was sentenced to three years in prison on counts involving evading income tax, false disclosure of the hush money paid to Stormy Daniels and another hush money charge Getty Criminals who worked for Trump Paul Manafort Former campaign manager for Trump Manafort was found guilty in February 2018 of five counts of tax fraud, two counts of bank fraud and one count of failure to disclose a foreign bank account. The crimes occurred prior to his appointment in Trump's campaign Getty Criminals who worked for Trump George Papadopoulos Former Trump campaign adviser Papadopoulos pleaded guilty to lying to the FBI in October 2017. He had lied about making contact with a professor who claimed that the Russians had dirt on Hillary Clinton. He was sentenced to 14 days in jail Getty Criminals who worked for Trump Michael Flynn Former White House National Security adviser Michael Flynn pleaded guilty to lying to the FBI in December 2017. He had lied about conversations that he had with the Russian ambassador to the US during Trump's Presidential campaign. He was not given prison time due to his "significant assistance" to the Mueller investigation Getty Criminals who worked for Trump Rick Gates Deputy chairman of Trump's presidential campaign Gates pleaded guilty to lying to the FBI in February 2018 AFP/Getty

Cohen pleaded guilty over the summer to failing to report more than $4m (£3m) in income to the IRS, making false statements to financial institutions and campaign-finance violations stemming from the hush-money payments he arranged for Ms Daniels and former Playboy model Karen McDougal. Cohen implicated Mr Trump in his guilty plea, saying the president directed him to make the payments during his 2016 campaign.

The records show the inquiry into Cohen had been going on since July 2017 – far longer than previously known – and that a big part of its focus was Cohen’s taxi businesses and misrepresentations he made to banks as part of a scheme to relieve himself of some $22m (£16.6m) in debt he owed on taxi medallion loans.

Tuesday’s release of the search warrant came nearly six weeks after US District Judge William H Pauley III partially granted a request by several media organisations that the search warrant be made public due to the high public interest in the case.

Many sections of the records dealing with the campaign-finance violations Cohen committed when he paid two women to stay silent about alleged affairs they had with Mr Trump were redacted. A judge ordered those sections to remain secret after prosecutors said they were still investigating campaign finance violations.

The judge acknowledged prosecutors’ concerns that a wholesale release of the document “would jeopardise an ongoing investigation and prejudice the privacy rights of uncharged third parties,” a ruling that revealed prosecutors are still investigating the campaign-finance violations.

The judge ordered prosecutors to redact Cohen’s personal information and details in the warrant that refer to ongoing investigations and several third-parties who have cooperated with the inquiry. But he authorised the release of details in the warrant that relate to Cohen’s tax evasion and false statements to financial institutions charges, along with Cohen’s conduct that did not result in criminal charges.

Support free-thinking journalism and attend Independent events

The FBI raided Cohen’s Manhattan home and office last April, marking the first public sign of a criminal investigation that has threatened Mr Trump’s presidency and netted Cohen a three-year prison sentence that he is scheduled to start serving in May. The agents, who also scoured Cohen’s hotel room and safe deposit box, seized more than 4 million electronic and paper files in the searches, more than a dozen mobile devices and iPads, 20 external hard drives, flash drives and laptops.