Washington: US President Donald Trump has accused Barack Obama of "wiretapping" his offices before the presidential election in November last year, claiming the former President had overseen a "Nixon/Watergate"-style intervention.
Launching a series of tweets on Saturday, Trump said: "Terrible! Just found out that Obama had my ‘wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!"
He also called Obama a "bad, or sick, guy".
"Is it legal for a sitting President to be "wiretapping" a race for President prior to an election? Turned down by court earlier. A NEW LOW!" he added in subsequent tweets.
"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 Election!"
The President then compared the alleged surveillance of his communications to Watergate -- the scandal in the early 1970s that brought down Republican President Richard Nixon after he ordered a break-in of the Democrats' Washington headquarters.
However, Trump did not immediately provide evidence that Obama was responsible for surveillance on his property, the Hill newspaper reported.
Moments earlier, Trump had also linked Obama to Attorney General Jeff Sessions's meetings last year with Russia's ambassador to Washington.
"The first meeting Jeff Sessions had with the Russian Amb was set up by the Obama Administration under education program for 100 Ambs," he tweeted.
Sessions on Thursday said he would recuse himself from any investigations into Russia's links to Trump's team, after massive outrage over the revelations that he met Russian Ambassador Sergey Kislyak twice during the campaign, then denied doing so during his confirmation hearings.
Trump also blasted Obama for meeting Kislyak 22 times and tweeted: "Just out: The same Russian Ambassador that met Jeff Sessions visited the Obama White House 22 times, and 4 times last year alone."
Trump's team has sought to push back on accusations of ties with Russia by pointing out instances of Democrats meeting Kislyak, according to the report.
Former National Security Adviser Michael Flynn was ousted last month after revelations that he misled top White House officials about the nature of his conversations with Kislyak.