Donald Trump alleges wire tapping by Barack Obama during US election campaign

In one of the Tweets, Trump said the alleged wire tapping took place in his Trump Tower skyscraper in New York, but there was “nothing found”.

Trump’s administration has come under pressure from FBI and congressional investigations into contacts between some members of his campaign team and Russian officials during his campaign.

Obama imposed sanctions on Russia and ordered Russian diplomats to leave the US in December over the country’s involvement in hacking political groups in the November 8 US presidential election.

Trump’s national security adviser, Michael Flynn, resigned in February after revelations that he had discussed U.S. sanctions on Russia with the Russian ambassador to the United States before Trump took office.

Flynn had promised Vice President Mike Pence he had not discussed US sanctions with the Russians, but transcripts of intercepted communications, described by US officials, showed that the subject had come up in conversations between him and the Russian ambassador.

Trump has often used his Twitter account to attack rivals and for years led a campaign alleging that Obama was not born in the US He later retracted the allegation.