US President Donald Trump has accused his predecessor of wire-tapping his phone a month before he was elected.
President Trump tweeted early on Saturday: “Terrible! Just found out that Obama had my “wires tapped” in Trump Tower just before the victory. Nothing found. This is McCarthyism!”
He went on to say that a court had earlier denied a wiretap request.
The US president has given no details to back up the claim – or suggested which court order he was referring to.
Media reports in the past few weeks have suggested the FBI had sought a warrant from the foreign intelligence surveillance court (Fisa) last summer in order to monitor members of the Trump team suspected of irregular contacts with Russian officials.
The warrant was first turned down but then approved in October, according to the media reports.
There has been no official confirmation and it is also not clear if this evolved into a full investigation.
There has been no comment yet from ex-President Barack Obama.
Mr Trump tweeted: “I’d bet a good lawyer could make a great case out of the fact that President Obama was tapping my phones in October, just prior to the Election.”
He called the alleged tapping “a new low” and said “This is Nixon/Watergate” – referring to the most notorious political scandal of 1972, which led to the downfall of President Richard Nixon after a web of political spying, sabotage and bribery was exposed by the media.
He also called it McCarthyism – the persecution for US Communists and their allies led by Senator Joe McCarthy in the 1950s.