Crystal Palace have been fined by the Premier League following last season's 'Spygate' affair.
Opponents Cardiff complained that their line-up had been leaked to the Palace camp ahead of a match on April 5 that the south London club won 3-0.
Palace denied the claims against them, with Eagles sporting director Iain Moody, who was sacked from a similar position at Cardiff earlier in the season, saying it was "incredibly, extraordinarily untrue" that he had any involvement in any wrongdoing.
The Premier League said in a statement on Monday: "The Premier League board has considered a complaint from Cardiff City regarding the conduct of a Crystal Palace official. The board found that Crystal Palace breached Rule B.16 and has exercised its summary jurisdiction and fined the club."
The rules states 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".
Palace face a fine of up to £25,000.
Moody joined Palace last November, weeks after being dismissed as head of recruitment at Cardiff during a stormy period for the Welsh club.
Palace declined on Monday to comment on the findings of the Premier League investigation, as did Cardiff, who were relegated at the end of last term.
In April, former Palace manager Tony Pulis said of the spying claim: "As a manager and as a coach, I log every session that I do, and I'll be taking those sessions up to the Premier League to show that I picked my team on Monday before we played Cardiff on the Saturday.
"That team was worked with for a week and there were no changes in it whatsoever."
The fine for Palace came in the wake of Pulis departing over unconnected issues, and an opening-day defeat to Arsenal in the Premier League.
Former Tottenham manager Tim Sherwood and former Cardiff boss Malky Mackay, who worked alongside Moody with the Bluebirds, are reportedly candidates to fill the vacant post at Selhurst Park.