The Sun last week quoted him as suggesting that Mel B had to be heavily persuaded to appear on the panel show due to Amstell's perceived bitchiness.
However, Fielding took to Twitter to deny the rumours, saying: "Just for the record I don't use words like cosy and I never said Simon ruined the Buzzcocks. He is my friend. Just for the record."
During his three-year stint as host on the show - which ended last year - Amstell upset Ordinary Boys frontman Preston and Vanessa Feltz.