US President Donald Trump has hit out at Barack Obama accusing his predecessor of having his "wires tapped" in Trump Tower.

Posting on Twitter, Mr Trump claimed this had occurred in October shortly before his presidential election victory in November.

Mr Trump also drew parallels with the 1970s Watergate scandal that forced President Richard Nixon to resign, referring to Mr Obama a "bad (or sick) guy".

Wire-tapping is strictly controlled worldwide, and in the case of the US, can only be permitted and authorised by a court.

Under the Foreign Intelligence Surveillance Act (FISA), federal intelligence agencies can ask for approval for wiretaps from the US FISA court, for which proceedings are secret.

It was revealed in January that intelligence agencies had obtained a FISA warrant in October.

The extraordinary claim comes after a week of trouble for the White House, which saw Trump fighting for his Attorney General Jeff Sessions as it was revealed he had misled the Senate.