Cavan-based Mannok says comments from Sean Quinn "undermine his condemnation of those engaged in violence".
In an interview on The Joe Finnegan Show last week, Mr Quinn condemned the 2019 attack on Kevin Lunney, calling it a "barbaric act" that "shouldn't have happened".
Three men were recently found guilty of falsely imprisoning and intentionally causing harm to Mr Lunney in Co Cavan.
However, in an article with The Sunday Independent, Mr Quinn told the paper: "Would you want to die as someone who has stolen goods or taken goods that didn't belong to them. I wouldn't want to die as that person."
A Mannok spokesperson says "baseless allegations by Sean Quinn are now a perennial occurrence and only serve to undermine his condemnation of those engaged in intimidation and violence who evidently are sympathetic of his views".
