The actor and comedian, also known for his turns on The Fast Show and Men Behaving Badly, was Bush Baby on the ITV show.
The panel had failed to guess his identity after his performance of Please Release Me by Engelbert Humperdinck, and he threw them off the scent with an Australian accent.
Asked by host Joel Dommett how he found performing in the mask, John joked: “I have to say as a northerner who doesn’t feel the cold, who is already covered in hair, it not been the greatest, there is a sense of relief.”
Afterwards he added: “I decided to take on the challenge because I’d originally been asked the year before but I was in the middle of filming Cold Feet. So, when the opportunity arose again, I decided to go for it.
“It was quite hard to keep a secret, the only people who knew where my partner, my ex-wife and my agent who booked me on the show. In regards to explaining trips to London, I just pretended it was for existing work that I already did.”
Discussing the secrecy at filming, he said: “Secrecy when filming was major, we were picked up by the driver who had signed an NDA and as we drew closer to the studio we had to don a mask, gloves and a sweatshirt with ‘don’t speak to me’ on it so nobody could guess our identity.
“Trips from the dressing room to studio also incorporated full disguise.”
Asked how he felt to leave at this stage of the competition, he said: “I got halfway, which was perfect for me as I wasn’t in it to win it.
“I did it for fun and I was very grateful to be able to work during the pandemic. I was also very relieved as the costume was very, very hot and uncomfortable.”
Before Bush Baby’s reveal, some of the names put forward for the character included Matt Lucas, Noel Fielding and Peter Andre.
The Masked Singer continues on ITV on Saturdays at 7pm.