Leeds boss Marcelo Bielsa has shouldered the full responsibility for the spy row ahead of the match with Derby at Elland Road.
County have claimed a man escorted from the perimeter of their training ground by police on Thursday after "acting suspiciously" was an employee of promotion rivals Leeds.
The Rams travel to Sky Bet Championship leaders Leeds on Friday night, with the two clubs separated by eight points in the table.
Derbyshire Police attended County's training ground on Thursday after a man was seen at the perimeter fence of the Moor Farm complex.
And the Rams claimed on Friday afternoon that the individual was a member of staff at the Yorkshire club.
Marcelo Bielsa on spy row
Argentinian boss Bielsa has claimed full responsibility for the stunt, telling Sky Sports through an interpreter: "It's true there was someone from Leeds United, 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 it's enough that Frank Lampard and Derby County felt it was not the right thing to do. I didn't behave well."
He added: "Yesterday I talked to Frank Lampard and he told me I didn't respect fair play.
"I have a different point of view on it but the important thing is what Frank and Derby think. I am responsible for it because I didn't ask for Leeds United permission to do it.
"Without trying to find a justification, I have been using this kind of practice since the qualifications for the World Cup with Argentina. This is not illegal, we have been doing it publicly, we talk about it in the press, for some people it is the wrong things, for others it's not."