Newly reviewed information has found that former US national security adviser Michael Flynn and other Trump aides were in contact with Russian officials or those connected with the Kremlin in at least 18 phone calls and emails in the final seven months of the US elections, Reuters reported Thursday.

The previously unknown communications were part of a body of the information now being reviewed by the FBI and congressional investigators who are examining ties between the Trump campaign and Russia amid suspicions of Russian meddling with the presidential vote.

Officials who spoke to Reuters on condition of anonymity noted that they “had seen no evidence of wrongdoing or collusion between the campaign and Russia in the communications reviewed so far.”

US President Donald Trump fired Flynn in February on grounds that he had misled US Vice President Mike Pence and other White House officials about his conversations with Russia’s ambassador to the US, Sergei Kislyak.

Six of the 18 contacts were between Kislyak and Trump advisers, including Flynn, according to three current and former officials.

On Wednesday the Trump administration appointed former FBI Director Robert Mueller as a special counsel to oversee the federal investigation into allegations Russia and Trump’s campaign collaborated to influence the 2016 presidential election.

In this Feb. 10, 2017 file photo, then-national security adviser Michael Flynn sits in the East Room of the White House in Washington. (AP Photo/Carolyn Kaster, File)

In this Feb. 10, 2017, file photo, then-national security adviser Michael Flynn sits in the East Room of the White House in Washington. (AP Photo/Carolyn Kaster, File)

Officials familiar with the material under review told Reuters that following Trump’s victory in the November 8 vote, Flynn and Kislyak discussed opening a line of communication between Trump and Putin that could “bypass the US national security bureaucracy, which both sides considered hostile to improved relations.”

The communications allegedly dealt with repairing US-Russian economic relations, cooperating against the Islamic State in Syria, and dealing with China.

In January 2017 the White House initially denied there was any contact with Russian officials during the campaign. However, since then administration officials have confirmed there were four meetings between advisers and Kislyak.

Reuters said it was did not receive any comments about the claims from White House, Flynn’s lawyer, or the Russian Foreign Ministry.

Contacts took place between April and November 2016. According to Reuters, it was during the same period that hackers, alleged by US intelligence to be working for Russia, tried to influence the outcome of the election in Trump’s favor.

Sources told Reuters that one of the people Trump aides were in contact with was Viktor Medvedchuk, a Ukrainian oligarch and politician. It was not clear with whom he spoke but the sources said the topics discussed were also about improving US-Russian cooperation. According to the report, Putin is godfather to Medvedchuk’s daughter.

Medvedchuk, in a email response to Reuters, said, “I am not acquainted with any of Donald Trump’s close associates, therefore no such conversation could have taken place.”

The identities of other Russian or Trump advisers who were in contact are being kept under wraps in intelligence reports due to privacy laws. If need be, US officials investigating the contacts could request that their identities be revealed.

In this June 19, 2013, file photo, former FBI Director Robert Mueller testifies on Capitol Hill in Washington. (AP Photo/J. Scott Applewhite, File)

In this June 19, 2013, file photo, former FBI Director Robert Mueller testifies on Capitol Hill in Washington. (AP Photo/J. Scott Applewhite, File)

Mueller’s appointment came as Democrats insisted ever more loudly that someone outside Trump’s Justice Department must handle the politically charged investigation. An increasing number of Republicans, too, have joined in calling for Congress to dig deeper, especially after Trump fired FBI Director James Comey who had been leading the bureau’s probe.

Earlier Wednesday, Trump complained in a commencement address that “no politician in history” has been treated worse by his foes, even as exasperated fellow Republicans slowly joined the clamor for an significant investigation into whether he tried to quash the FBI’s probe.

Three congressional committees, all led by Republicans, confirmed they wanted to hear from Comey, whose notes about a February meeting with the president indicate Trump urged him to drop the bureau’s investigation of fired National Security Adviser Michael Flynn. Congressional investigators are seeking Comey’s memos, as well as documents from the Justice Department related to the firing.

Many Democrats also were calling for an independent special counsel, or prosecutor.