Scott Davidson was a firefighter who sadly died during the attacks on the World Trade Center in 2001.
In 2016, Carr was taking part at the Comedy Central roast of Rob Lowe.
Whilst Davidson was sat listening on the panel, Carr joked: "I'm appalled that people would come here and make jokes about the sacrifice Pete's heroic father made on 9/11.
"This is not the roast of Pete Davidson's father.
"That was in 2001."
As grim as the joke might be, the Saturday Night Live host looked to take it in good spirits and even dubbed the joke as 'dope'.
Well, on episode #145 of Have A Word Podcast last year, Carr revealed he first 'tested' the joke at the Hollywood Improv comedy club in LA.
He said: "It get's a laugh and then a 'ooh', like it's funny but 'f***'.
"And then there's a laugh from the back of the room, like a sustained f***ing maniacal laugh from the back of the room."
To which, Carr remarkably reveals was Pete Davidson himself.
He continued: "And you went 'ok', because it's one of those where it's that spicy enough where I wouldn't do it without checking.
"And also I really admire Pete, I like Pete a lot, I think he's a good guy."
The comedian has recently faced a backlash following his Netflix special joke about the holocaust.
The comedian dropped His Dark Material on Christmas Day and has been called out for a joke he made about Travellers. Carr told the audience: "Strap in everyone, you ready?"
He begins the joke with: "When people talk about the Holocaust, they talk about the tragedy and horror of six million Jewish lives being lost to the Nazi war machine.
"But they never mention the thousands of gypsies that were killed by the Nazis.
"No one ever talks about that because no one wants to talk... about the positives."
The joke caused an uproar on social media and The Traveller Moment, a group of people who aim to uphold 'the rights of Gypsy, Roma and Traveller people', also commented on the clip.
They wrote: "This is truly disturbing and goes way beyond humour. We need all your support in calling this out."
One user wrote: "This is shocking he should be ashamed of himself and the audience laughing."
Someone else commented: "How is this ok... He should be ashamed of himself."
Featured Image Credit: Comedy Central/Alamy
Topics: Jimmy Carr