The Italian told Italian news agency ANSA in 2005 "I am a fascist, not a racist", and his appointment on Sunday to succeed Martin O'Neill prompted former foreign secretary David Milliband to stand down as Sunderland's vice-chairman and non-executive director.
But in a statement released on Monday by the club, Di Canio said: "I don't have a problem with anyone. I don't know why I have to keep repeating my story, to be defending myself on something that doesn't belong to me every time I change clubs.
"Talk about racism? That is absolutely stupid, stupid and ridiculous."
Miliband announced on Sunday on his own website: "In the light of the new manager's past political statements, I think it right to step down."
But former Swindon chairman Jeremy Wray, who gave Di Canio his first chance in management, dismissed that stance as a "sad knee-jerk reaction". And Di Canio said: "What I can say is that if someone is hurt, I am sorry. But this didn't come from me - it came from a big story that people put out in a different way to what it was.
"The people who know me can change that idea quickly. When I was in England my best friends were Trevor Sinclair and Chris Powell, the Charlton manager - they can tell you everything about my character.
"I don't want to talk about politics because it's not my area. We are not in the Houses of Parliament, we are in a football club. I want to talk about sport. I want to talk about football, my players, the board and the fans. I don't want to talk any more about politics - I am not a politics person."
Sunderland's chief executive officer Margaret Byrne added in the same statement: "Sunderland AFC is a traditional football club, with a rich and proud history. It has a strong ethos and ethics and that has not changed in any shape or form.
"Naturally it's been very disappointing to read some of the reaction to Paolo's appointment in the last 24 hours. Anyone who has met Paolo and spoken with him personally, as we did in depth before making this appointment, will know that he is an honest man, a man of principle and a driven, determined and passionate individual."
Sunderland dismissed O'Neill on Saturday evening following the club's 1-0 home defeat against league leaders Manchester United. That result left the Black Cats without a win in eight games and just a point clear of the relegation zone.
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