Howard Stern said he was “all in on Joe Biden” as he backed the presumptive Democratic nominee for president, spurning his old friend Donald Trump.

The radio legend criticised the president for his handling of the coronavirus pandemic on his SiriusXM show on Monday — in particular his suggestion that the injection of disinfectant might help to treat the virus.

Howard Stern regularly had Donald Trump on his show (Kevin Kane/Getty Images For The Rock and Roll Hall of Fame)

"What's it going to take? I don't get it. I don't think there is anyone left who will vote for him," Mr Stern said.

"You see the wall that's right next to you, I'll vote for the wall over a guy who tells me that I should pour Clorox into my mouth. Listen, I think we are in deep shit. I think we could have been ahead of this curve."

Mr Trump was a regular guest of Stern’s in the years before he became president, when the show was infamous for its shock value and controversial treatment of women.

In recent years, Mr Stern has toned down the lewdness that propelled him to the top of the radio world and focused on interviews with high profile celebrities.

Previous comments made by Mr Trump on the show surfaced throughout the 2016 campaign, at a time when he was already under fire for the emergence of a 2005 “Access Hollywood” audio tape in which he bragged about grabbing women by the genitals. In 2004, Mr Trump said on Mr Stern’s show that "deeply troubled" women are "always the best in bed," according to a CNN report.

Mr Stern refused to replay the tapes of the president's troubling appearances in the midst of the controversy, however, saying it would be a “betrayal” to do so.

“I feel Donald Trump did the show in an effort to be entertaining and have fun with us and I feel like it would be a betrayal to any of our guests if I sat there and played them now where people are attacking him,” he said at the time.

Mr Stern also endorsed Hillary Clinton in the 2016 election against Mr Trump, and interviewed her in December last year.