US investigators said they have corroborated some of the communications in a 35-page Russian dossier reported CNN.
It was reported last year that Russian operatives have a raft of comprising material on Donald Trump that they are holding to use against him.
US intelligence chiefs briefed Trump and then outgoing President Barack Obama on the damaging allegations.
The allegations included reports that the Russian regime "has been cultivating, supporting and assisting Trump for at least five years" and that Trump was allegedly involved in "perverted sexual acts" during a visit to Moscow.