Trump at the time offered no evidence to back his extraordinary and unsubstantiated allegation, which he made on Twitter. Obama, the Justice Department and the FBI all denied there was any such evesdropping.

President Donald Trump stunned many in March 2017 when he accused former President Barack Obama of “wire tapping” Trump Tower during the 2016 campaign.

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

Is it legal for a sitting President to be "wire tapping" a race for president prior to an election? Turned down by court earlier. A NEW LOW!

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!

How low has President Obama gone to tapp my phones during the very sacred election process. This is Nixon/Watergate. Bad (or sick) guy!

Then White House press secretary Sean Spicer tried to claim that Trump hadn’t really accused Obama of “wire tapping,” even though that’s the term the president used in his posts.

On Thursday night, Trump finally admitted during a 45-minute interview with Fox News host Sean Hannity that he made the allegation based on “a little bit of a hunch.” Trump also expressed surprise at how his baseless accusation had blown up “like you’ve never seen.”

“I don’t know if you remember, a long time ago, very early on I used the word wiretap, and I put in quotes, meaning surveillance, spying you can sort of say whatever you want,” Trump told Hannity.

“Now I understand why, because they thought two years ago when I said that just on a little bit of a hunch and a little bit of wisdom maybe, it blew up because they thought maybe I was wise to them,” he continued. “Or they were caught. And that’s why. ’Cuz if they weren’t doing anything wrong it would’ve just gotten by, nobody would’ve cared about it.”

He added: “It was pretty insignificant, I thought when I said it, and it’s pretty amazing.”

The president’s comments on his old claim came during a lengthy self-pitying rant alleging improper behavior by federal investigators, including Peter Strzok and Lisa Page, during and after the 2016 campaign. Trump described the investigation as “a coup and spying.”

Check out Trump’s “wire tapping” admission from the 3:50 mark below: