Leeds admitted to having an employee observe Derby County's training session.
Leeds United have been fined £200,000 after an EFL investigation found them in breach of league regulations in relation to the controversial incident at Derby County's training ground in January.
A Leeds employee was caught observing a Derby training session ahead of the Championship fixture between the two sides on January 11, which Leeds went on to win 2-0.
Bielsa later admitted to sending a member of his staff to take in the session, and after an investigation was conducted into the incident, they have been reprimanded and issued with a £200,000 fine by the league's regulatory body.
A joint statement from the club and the EFL reads: "After finalising its investigations into the incident at Derby County’s training ground on Thursday 10 January, the EFL reached the conclusion that the conduct undertaken by Leeds United in observing opponents’ training sessions, is a breach of Regulation 3.4.
"Regulation 3.4 provides that ‘in all matters and transactions relating to the League, each club shall behave towards each other Club and The League with the utmost good faith.’
"Leeds United has fully co-operated with the EFL’s inquiries and following a comprehensive review of all the evidence provided, the Club has now formally admitted a breach of Regulation 3.4.
"As a consequence the Club has been fined £200,000 (inclusive of a contribution to costs) and received a formal reprimand and warning to the effect that the Club’s conduct fell significantly short of the standards expected by the EFL and must not be repeated."
It continues: "In addition, Leeds United has agreed to support a new EFL Regulation that make it clear that Clubs will be expressly prohibited from viewing opposition training in the 72 hours immediately prior to a fixture, unless invited to do so."