US President Donald Trump on Saturday accused former President Barack Obama of wiretapping him in October during the late stages of the presidential election campaign, but offered no evidence to support the allegation.

"How low has President Obama gone to tap my phones during the very sacred election process. This is Nixon/Watergate. Bad (or sick) guy!," Trump said in a series of tweets on his Twitter account early on Saturday. "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!"

Obama's office did not immediately respond to a request for comment from Reuters. The White House also did not respond to a request to elaborate on Trump's accusations.

Former Obama adviser Ben Rhodes strongly denied Trump's allegations.

"No president can order a wiretap. Those restrictions were put in place to protect citizens from people like you," Rhodes wrote on Twitter.