According to law enforcement and other U.S. officials, Trump adviser Carter Page was monitored as part of an investigation into potential links between the campaign and Russia.

The FBI had obtained a court order to do that last summer, after they had convinced Foreign Intelligence Surveillance Court judge that there was reason to believe that Page was acting as an agent of foreign power.

While Carter Page has not yet been accused of any crimes, it's not clear whether it will happen at all, since the majority of similar investigations end without filing any criminal charges.

The information was obtained by Washington Post whose sources were only willing to speak about it if full anonymity was promised, considering they are not allowed to discuss the probe.

Page himself ha denied any wrongdoing with the campaign and said that "This [revelation] confirms all of my suspicions about unjustified, politically motivated government surveillance."