Ahead of Friday's Championship game in English football's second tier between Leeds and Derby County, Bielsa admitted to sending a spy to watch the opposition at their training ground on Thursday.On Saturday, Leeds said its owner Andrea Radrizzani had met with Derby County counterpat Mel Morris "to formally apologize for Marcelo's actions.""Following comments made by Marcelo Bielsa yesterday the club will look to work with our head coach and his staff to remind them of the integrity and honesty which are the foundations that Leeds United is built on," said a Leeds statement on its website.READ: Gold-coated steak backlash earns Ribery 'heavy fine''Spygate'The incident has been dubbed "spygate" by Britain's media."I am responsible for it," Bielsa, who managed the Argentina national team between 1998 and 2004, told Sky Sports on Friday."It doesn't matter if this is legal or illegal, or right or wrong ... for me, it is enough that Frank Lampard and Derby felt it was not the right thing to do, for me to believe that I didn't behave well," added Bielsa, referring to the Derby manager."Yesterday I talked to Frank Lampard and he said I didn't respect the rules of fair play. I have a different point of view on it, but the important thing is what Frank Lampard and Derby think."I am the only one responsible for it, because I didn't ask for the permission of Leeds to do it."Without trying to find a justification, I have been using this kind of practice since the qualifiers for the World Cup with Argentina. It is not illegal, we have been doing it publicly and we talk about it in the press."READ: Why history is with Liverpool in Premier League title race'Lack of respect'Leeds won Friday's game 2-0 to move five points clear at the top of the Championship to leave Derby 11 points behind in sixth place."On a sportsman's level, it's bad," Lampard told Sky Sports. "If we are going to talk about culturally and say I did it somewhere else and it's fine, I don't believe that."It's disrupted our build-up to the game. People will say I am making an excuse, but I will speak like this after the game whether we win, lose or draw."British football writer Henry Winter tweeted that the 63-year-old Bielsa had shown "a complete lack of respect for his peers."However, former Manchester United defender and England international Gary Neville, who managed La Liga club Valencia, said "spying" on the opposition was "quite normal" in Spain, adding that he admired Bielsa "for fronting up and also stating he's always done it."Visit CNN.com\/Sport for more news, features and videos It's a practice that also seemingly goes on in Germany's Bundesliga, according to German football writer Rafa Honigstein."This December, Hoffenheim caught a Werder Bremen scout spying on their training with a drone. Werder apologised," tweeted Rafa Honigstein. "Hoffe coach Nagelsmann: "I'm not really angry at the analyst doing his job. It's commendable if they're doing everything they can, trying to spy on the opposition."Leeds last played in the Premier League during the 2003-2004 season.