During an interview on KIIS FM’s breakfast program on Thursday alongside his Today co-host, Allison Langdon, Karl lashed out once again at his former colleague.
'When Richard mentioned [the hair plugs] on I'm a Celebrity, what were your thoughts on that, Karl?' asked radio personality Jackie 'O' Henderson.
Karl replied: 'Richard and I have had a beautiful relationship over many years and, well, I'll just say this, I never really saw him in person because he was always too busy flapping about.
'And so when he said it, I had to turn off that show and I just thought, "You are just a tosser." Richard Reid is a tosser of the highest order!'
Shortly after Karl completed his interview, Richard spoke to Kyle and Jackie O via telephone to offer his – very different - side of the story.
According to Richard, he and Karl had never got along during their seven years working together on the Nine breakfast show.
He also defended his hair transplant revelation by saying he had “kept Karl's name in the headlines... when he didn't have a job” at Today.
He added with a laugh: “At least I'm a tosser of the highest order! Does that mean I get a crown or a medal?”
When Kyle Sandilands asked directly if Richard had a problem with his ex-colleague, he replied sarcastically: “I like Karl just fine. I like him just fine in small doses.
"I don't have a problem with Karl... not much.”
However he admitted he disliked Karl for “talking about himself in the third person” and for being “full of himself” on set of the Today show.
On last year’s I’m A Celeb, Richard stunned viewers after spilling how he discovered Karl had secretly got a hair transplant.
“So I go into the hair room, and this guy looks up and he's kind of balding... It was Karl Stefanovic without his spray-on hair!
“And then he went away and got hair plugs. He had one of those six-week vacations and came back with [makes gesture for hair plugs].
“And he still used the spray-on until it filled in.”