Leeds have been fined $322,000NZD by the Football Association for homophobic chanting in their match with Brighton.
The incident occurred during their 2-2 home draw with the Seagulls in the Premier League in March.
In its written reasons, the independent commission said: "The use of the phrases is obviously and plainly discriminatory and highly derogatory."
Leeds have accepted the fine and said in a statement they "need to increase work we are doing with our fanbase".
Among a number of findings of the incident that happened around the 20th minute of the match, the commission said: "The volume of the chanting leads to the inevitable conclusion that a very considerable number of Leeds supporters engaged in this homophobic chanting and that it was not a brief event.
"This conclusion is supported by the fact that the post-match complaint was based on the chanting being clearly audible on national radio."
It added: "There were very substantial deficiencies as to pre-match planning by Leeds."The fact that [at most] only two [and perhaps no] Leeds supporters have been identified for this offensive behaviour is disappointing but reflective of a lack of any or any proper contingency planning.
"The commission categorised the culpability of Leeds in its lack of proper pre-match planning, lack of properly evidenced immediate appropriate reaction to the misconduct, and lack of properly evidenced post-match response as high."
Leeds have also been given an action plan that requires them conduct a full review of their stewarding and "evaluate their current CCTV capabilities".
The Whites were relegated to the Championship last season and have taken one point from their two games so far this campaign.
-Reuters