President Donald Trump has accused his predecessor Barack Obama of “wire tapping” Trump Tower just before the presidential election last November. The allegations were made in a series of tweets early Saturday.

"Terrible! Just found out that Obama had my 'wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!," Trump tweeted.

The 70-year-old also called the alleged move “a new low.”

He, however, did not back his accusations with evidence, only stating that the wire tap happened last October.

Trump is known to make several claims, which he often does not substantiate.

The allegations come months after U.S. authorities said Russia hacked the Democratic Party servers in the run-up to the 2016 elections, possibly swaying the polls in favor of Trump. Moscow has denied any wrongdoing and Trump previously said that the cyberattack did not happen.

This is not the first time Trump has personally accused Obama of wrongdoing. In 2011, and in the years following that, he raised doubts on the then president’s actual birth place — getting involved in the so-called “birther” conspiracy theory.

"Our current president came out of nowhere. Came out of nowhere," he said in a speech at Conservative Political Action Conference at the time. "In fact, I'll go a step further: The people that went to school with him, they never saw him, they don't know who he is. It's crazy."

However, during his 2016 presidential campaign, he admitted that Obama was indeed born in the U.S.

The latest allegations also follow recent reports documenting Trump team’s relations and alleged interactions with Russia. Last month, the president’s national security advisor Michael Flynn resigned after accepting that he misled Vice President Mike Pence over whether the topic of sanctions on Moscow was brought up during his talks with Russian officials.

“I inadvertently briefed the vice president-elect and others with incomplete information regarding my phone calls with the Russian ambassador,” Flynn said in his resignation letter. “I have sincerely apologized to the president and the vice president, and they have accepted my apology.”

According a recent report by the New York Times, phone records and intercepted calls showed Trump’s election campaign and several aides were in constant touch with senior Russian intelligence authorities prior to the election. The alleged communications were discovered during an investigation into the Russian cyberattacks.