Derby travel to Championship leaders Leeds in a crucial top-of-the-table clash on Friday night and the local constabulary put out a tweet saying '#spyingischeating' after the incident.
The manager accepted responsibility for the decision to deploy a "spy" to watch Derby's preparations.
"I am the only one responsible for it, because I didn't ask for the permission of Leeds to do it". I am responsible for it. "The responsibility of this is me, I am responsible, there is some precision that I need to give".
"It doesn't matter if this is legal, illegal, right or wrong". For me to see that, to believe that. I didn't behave well.
'Well that's good. I spoke to him yesterday afternoon myself and he did the same to me so I'm pleased he's gone again and said that.
The man has since been confirmed as a member of Leeds United's "footballing staff". I have a different point of view, but the important thing is what he and Derby think.
"The club is now in discussion with Leeds United club officials in relation to this incident". "There is nothing wrong to try to find information and know a bit more about what the opponents are doing". I've been using this kind of practice since the World Cup qualifiers with Argentina. This is not unlawful, not illegal.
Leeds are yet to issue a formal statement on the matter but Bielsa hasn't legally done anything wrong.
Derby County midfielder Mason Mount has warned Leeds United that results suggest the Rams have extra desire to punch above their weight when they are playing away from home.
Tonight, the FA said: "We are aware of the incident at Derby County's training ground and we will be investigating the matter".
Lampard called the incident "bad", telling Sky prior to the match that "if we are going to start talking about 'culturally I did it somewhere else and it was fine, ' then that doesn't work for me".
Earlier a Derbyshire Police statement had confirmed a man was removed from a position near the club's training ground. We were training on team tactics, team shape, personnel, how we are going to press, how we will work off the ball, the fact Harry Wilson wasn't training would become evident, so the person who is watching will see all of that.