Leeds United have made a formal apology and reminded manager Marcelo Bielsa of his responsibilities in the wake of the spying row that overshadowed Friday's 2-0 win over Derby.
Bielsa's side went five points clear at the top of the Championship but the coach admitted he made a mistake in sending a club employee to spy on Derby training leading up to the match.
Derbyshire Police confirmed on Friday that "a man was found at the perimeter fence of Moor Farm and was spoken to."
A Leeds United statement on Saturday read: "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.
"Our owner Andrea Radrizzani has met with Derby County's owner Mel Morris to formally apologise or Marcelo's actions.
"We will make no further comment on this matter."
Speaking after the win over Derby, Bielsa told Sky Sports: "I have to accept that in this country it's not something that is common, but it doesn't make me a person who cheats."
The Football Association is aware of the incident we will be investigating the matter, while the EFL have confirmed Derby have yet to make a formal complaint.
Derby boss Frank Lampard said before Friday's trip to Elland Road that his side's preparations for the match were disrupted, labelling the episode "bad."
"For me, it's not right," Lampard told BBC Radio 5 live after the match. "I'm a big fan from afar of Bielsa, I've got his book at home in my front room, but that's slightly clouded it for me today."