Former Trump campaign chairman Paul Manafort 'wiretapped before and after election'

The FBI reportedly wiretapped Paul Manafort, the former chairman of the Trump campaign, before and after the presidential election. 

Investigators collected communication that has fuelled fears that Mr Manafort had encouraged the Russians to help the campaign, three investigation sources told CNN. However, two of the sources said the evidence was not conclusive. 

Mr Manafort, who is at the centre of the Russia probe that has embroiled the White House this year, was known to talk to Donald Trump early this year. While the surveillance covered this time, CCN said, it is not known if the president was picked up by the surveillance.

Robert Mueller, the special counsel investigating possible election meddling by Russia and its alleged links with the Trump campaign, has been given details of the communication, the US broadcaster reported.

His prosecutors have also warned Mr Manafort to expect an indictment, the New York Times reported, citing two people close to the investigation. 

The surveillance, authorised by the court that handles the Foreign Intelligence Surveillance Act (FISA), started as far back as 2014 when the FBI was probing work done by a group of Washington consulting firms for Ukraine's former ruling party, CNN reported.

Sources told the broadcaster that the snooping was stopped at some point last year due to a lack of evidence, but it began again after the FBI secured another Fisa warrant as it investigated the Trump campaign's links with Russia. The warrant lasted until early this year. 

Such warrants require enough evidence to suggest the subject of the wiretapping may be acting as an agent of a foreign power.

The White House and Mr Manafort have yet to comment. 

Drafted in as Mr Trump’s campaign manager in March 2016, Mr Manafort replaced Corey Lewandowski and was brought in to shore up Mr Trump's primary campaign team.

He only lasted five months, however – resigning on August 19 after a slew of damaging accusations about his ties to Russia, and a high-profile reshuffle of Mr Trump’s team.