The special counsel Robert Mueller reportedly has evidence connecting President Donald Trump's longtime personal lawyer, Michael Cohen, to a shadowy trip to Prague in 2016.

Details of the alleged trip first emerged in the so-called Steele dossier, which said Cohen traveled to Prague to meet with Kremlin representatives to discuss how to "clean up the mess" resulting from revelations about former Trump campaign chairman Paul Manafort and former campaign adviser Carter Page in the summer of 2016.

If Mueller does have evidence linking Cohen to the Prague trip, it would be one of the most significant connections between the Trump campaign and Russian interests during the election.

The special counsel Robert Mueller has evidence linking Michael Cohen, President Donald Trump's longtime lawyer, to a secret trip to Prague in the summer of 2016, McClatchy reported Friday.

Mueller was appointed special counsel last year after Trump fired FBI director James Comey. He is tasked with investigating Russia's interference in the 2016 US election and whether the Trump campaign colluded with Moscow to tilt the race in his favor. Mueller is also looking into whether the president sought to obstruct justice when he fired Comey in May.

Details of Cohen's possible trip to Prague first publicly emerged in a dossier, which alleges collusion between the Trump campaign and Russia, compiled by the former British spy Christopher Steele.

The document cited a "Kremlin insider" as saying that there were "clandestine meeting/s between Republican presidential candidate Donald Trump's lawyer Michael COHEN and Kremlin representatives in August 2016."

"The Kremlin insider clearly indicated to his/her friend that the reported contact/s took place in Prague, Czech Republic," it said.

The document further alleges Cohen met with individuals linked to the Russian government, including Konstantin Kosachev, a member of Russia's parliament, and Oleg Solodukhin, who works with the Russian Center for Science and Culture.

It also claims Cohen, Kosachev, and others, including Romanian hackers, discussed "how deniable cash payments were to be made to hackers in Europe who had worked under Kremlin direction against the Clinton campaign," and ways to "sweep it all under the carpet and make sure no connection could be fully established or proven."

If Mueller does have evidence that Cohen traveled to Prague, it would be a monumental development in the Russia investigation.

Its significance stems from the fact that the timeframe of Cohen's alleged trip came following a series of damaging revelations about members of the Trump campaign during the summer of 2016. The dossier said the purpose of Cohen's trip was to mitigate the resulting fallout from those events.

Carter Page's Moscow trip

Carter Page Sergei Karpukhin/Reuters

Carter Page, who served as a foreign-policy adviser to the Trump campaign, traveled to Moscow in early July 2016. The dossier alleges Page met with top Russian officials on the trip who raised the possibility of offering Page a 19% stake in the state-owned company Rosneft in exchange for the US lifting sanctions on Russia if Trump became president.

It also alleges that a former Russian security official, Igor Diveykin, informed Page that the Kremlin had a dossier of kompromat on Democratic nominee Hillary Clinton that it wanted to give the Trump campaign.

Page has slammed the document as "fake news" and often calls it the "dodgy dossier." However, he testified to the House Intelligence Committee last year that he had several contacts with Russia-linked individuals, at times with the Trump campaign's knowledge.

WikiLeaks' email dump

On July 22, the radical pro-transparency group WikiLeaks, which has been described by CIA director Mike Pompeo as a "non-state hostile intelligence service," published the first batch of hacked Democratic National Committee emails. The US intelligence community concluded that the emails were stolen by hackers aligned with Russian interests, and that WikiLeaks was used as a tool of the Russian government.

Trump has repeatedly praised WikiLeaks and the email dumps. Five days after the first batch of emails was published, Trump publicly called for Russia to find thousands of emails Clinton deleted from her server.

"Russia, if you're listening, I hope you're able to find the 30,000 emails that are missing," Trump said at the time.

Paul Manafort's resignation

Paul Manafort. Thomson Reuters

Meanwhile, on July 19, The New York Times reported on financial records Trump campaign chairman Paul Manafort had filed in Cyprus which showed he was $17 million in debt to pro-Russian interests when he joined the campaign in March.

Shell companies connected to Manafort during his time working for Ukraine's pro-Russia Party of Regions had bought the debt, the report said.

The following month, it emerged that the Party of Regions had earmarked $12.7 million in undisclosed cash payments for Manafort in return for his work with the party from 2007 to 2012.

Three days later, on August 19, Manafort resigned from the campaign.

The dossier said Cohen's visit to Prague was made to "clean up the mess" resulting from the revelations about Page's Moscow trip and Manafort's Russia ties. If Mueller does in fact have evidence connecting Cohen to the alleged trip, it would raise a new set of questions about whether, and to what extent, Trump and other campaign associates had knowledge of the event.

Cohen has worked for Trump for over a decade, and he has been described at different times as Trump's fixer, pit bull, and consigliere. And in a separate criminal inquiry from the Mueller probe, the Manhattan US attorney's office is investigating Cohen for possible bank fraud, wire fraud, and election law violations. Both the Mueller investigation and the Manhattan US attorney's office are said to be examining Cohen's unofficial role on the Trump campaign.

A possible loophole

Michael Cohen. Jonathan Ernst/Reuters

In addition to the special counsel, congressional investigators have also signaled particular interest in Cohen's travel to Europe. Indeed, the alleged Prague trip was a subject of focus in the House Intelligence Committee earlier this year, as Democrats and Republicans on the panel debated the merits of the Russia probe and the FBI's investigative methods.

McClatchy reported that lawmakers' interest in Cohen's whereabouts in 2016 was further fueled by what they consider to be weak documentation Cohen provided to show them where he was — New York and Los Angeles — at the time of the alleged Prague visit.

Cohen has slammed the allegations contained in the dossier as "fake news," and accounts corroborating his version of events have surfaced since the material in the dossier, which is unverified, was published in full by BuzzFeed last year.

After he was widely criticized last year for tweeting out a photo of his passport cover as proof that he didn't visit Prague in 2016, Cohen showed the inside of the document to BuzzFeed. According to the outlet, Cohen's passport did not contain a stamp for the Czech Republic.

However, investigators working for Mueller have reportedly obtained evidence that Cohen first flew to Germany in late August or early September of 2016, and then traveled to the Czech Republic through another means of transportation. Were that the case, Cohen may not have needed a passport because both Germany and the Czech Republic lie within the Schengen Area, which encompasses 26 European countries and functions as a single jurisdiction for international travel.