Leeds United manager Marcelo Bielsa has admitted sending a spy to watch Derby's training session.
The Mirror report Bielsa told Sky Sports: "I am responsible for this incident. It's not about being legal or illegal or right or wrong.
"I'm responsible for it and didn't ask the permission of Leeds United to do it. I have been using this practice since the qualifications of the World Cup in Argentina.
"It is not illegal and we have talked about it publicly and in the press."
The comments are quite remarkable and were put to pundit Jermaine Jenas on BBC Radio 5 Live.
Jenas slammed Bielsa's behaviour, commenting: "Its disguisting. Its out of order. I don't see how it doesn't have any negative implications on the team.
"Its not the right thing to do, he needs to stop doing it
"The bottom line of it is he's cheated."
Bielsa is known for his maverick methods but this is quite unheard of in British football.
The FA are investigating the matter and may seek to punish Leeds despite there being no specific laws against it.
This story is going to run and run.