Redbridge Jewish Care A have been thrown out of this season's Peter Morrison Trophy after they were found guilty of fielding an ineligible player in the quarter-final against Hendon United Sports Club A.
RJC have 14 days to appeal. Hendon have been reinstated into the competition.
The National Football Committee heard the appeal on Monday night from RJC in Edgware.
A statement from the NFC said: "Under rule 8(d), Redbridge Jewish Care A were found to have played an ineligible player in their game against Hendon A on January 29, 2012 and the decision of the disciplinary hearing committee was to award the game to Hendon United A."
It remains to be seen whether or not RJC will appeal.
Following the decision, the club made the following statement: "The Management Committee of Redbridge have received the decision from the Peter Morrison appeal hearing and are extremely saddened by its findings.
"We are guilty of an administrative error only which we have openly acknowledged, but do not accept that we played an ineligible player .
"We are now looking at our options, not least of which is an appeal to the FA."
In the meantime, Hendon have been reinstated into the competition, meaning the treble is back on.
Hendon manager David Garbacz said: "I wouldn't like to be in the shoes of the person responsible for making the decision to play the ineligible player – his cornflakes can’t be tasting all that great this morning.
"They had no need to do it as they had more than enough players on the day.
"I don't think the committee had any option but to expel Redbridge as they knew exactly what they were doing even to the extent that the player involved gave the wrong name to the ref when he got booked.
"I feel sorry for the Redbridge players and staff who were not involved, but to be perfectly honest we won’t be shedding too many tears.
"It has given us an unexpected lifeline which we will be going all out to make the most of – the treble is back on and all the boys are raring to go."
Update: Redbridge have indicated that they will appeal the National Football Committee's decision to expel them from the competition.
The JC understands that Redbridge player Richie Caplin was scheduled to play for the club's B team against Shirley Park in October. He picked up an injury before kick-off and did not play, although his name remained on the teamsheet. Caplin featured in the recent match against Hendon, but gave a false name when booked.
PETER MORRISON TROPHY SEMI-FINAL DRAW
South Manchester Sports Club vs Oakwood
Brady A vs Hendon A or Hyde Park Rovers
Dates to be confirmed in due course