The Maltese professor believed to be the link between the Trump campaign and Russian officials is no longer turning up for work at the private university in Rome where he teaches, according to CNN.

Joseph Mifsud was identified as the mystery figure in the US special counsel investigation into Russian influence over the 2016 US presidential election.

His role emerged from court documents filed in relation to charges against former Trump aide George Papadopoulos, who claimed that Prof. Mifsud told him in April 2016 that the Russians had "thousands of emails" relating to Hillary Clinton.

Read: Maltese professor denies discussing Clinton emails with former Trump aide - Italian media

When his name emerged, Prof. Mifsud had downplayed his role and the extent of his contacts, but CNN has since unearthed more details which dispute his version of events.

One of his associates told CNN that Prof. Mifsud repeatedly bragged about how Moscow had "compromising material" on the Clinton campaign in spring 2016.The FBI affidavit implies Prof. Mifsud may have been "played" by the Russians.

"The Russian government and its security and intelligence services frequently make use of non-governmental intermediaries to achieve their foreign policy objectives," it said. "The Russian government has used individuals associated with academia and think-tanks in such a capacity."

Read: 'Nothing sinister' about Mifsud's Russian contacts - former employer

Two members from the Institute of Global Studies in Moscow told CNN on Tuesday that Prof. Mifsud presented himself as someone who could build contacts to foreign universities and institutes. They said several of the institute's officials visited the now-closed London Academy of Diplomacy, which Prof. Mifsud helped run.

“People who know him say Mifsud was always networking and often exaggerated his access to decision-makers. His stories are frequently contradictory. He has denied knowing anyone in the Russian government yet had previously claimed to have had an exchange with Foreign Minister Sergey Lavrov at an event. Nor is there any evidence to support a claim by Mifsud that he met President Putin,” CNN reported.

The "Putin niece" that Papadopoulos mentioned to the Trump campaign turned out to be a “simple student, very beautiful”, he is reported to have told La Repubblica: "Like many other students, I introduced her at the London Centre where Papadopoulos was, and he showed an interested in her that was not academic."

"Mifsud's history of exaggerations, and his enthusiasm to be seen as an important player in demand at conferences the world over, may now be coming back to haunt him," CNN concluded.

Read: Maltese professor suspected of Trump campaign link made many Russia trips