Ulster GAA has admitted that there was a link between clusters of coronavirus cases and clubs that played in county finals.
Both the Tyrone and Derry senior football finals are under police investigation for potential breaches of Covid-19 regulations over apparent lack of social distancing from spectators.
Ulster GAA chief executive Brian McAvoy said evidence had emerged within the past week leading to Monday’s decision to indefinitely suspend club matches across Ireland.
Mr McAvoy said club championships ended because "a very small minority" of fans allowed their "hearts ruling their heads" during celebrations resulting in coronavirus clusters.
He said the resulting public outcry meant it had to cancel future club games after damage to the reputation of the whole organisation.
"Unfortunately in some cases, and I have would to say a very small minority but still even that minority is too many, we have unfortunately seen people's hearts ruling their heads," Mr McAvoy said.
"We've had to act. We are a community organisation, we have wider responsibilities beyond the playing of our game.
"We just felt that the recent events were not portraying us in a positive light and it was unfortunately necessary to halt club activities.
"We are finding clusters of members of GAA clubs are testing positive, and invariably they are linked to teams that were playing in a county final of some sort.
"This has only become an issue in recent times, and it seems to coincide with county finals and a local community celebrating," he told BBC's Sportsound Extra Time
Derry GAA said it had moved its final between Slaughtneil and Magherafelt was moved out of Celtic Park to Bellaghy in the Mid-Ulster Council area, after stricter Covid-19 restrictions were introduced in the Derry and Strabane Council area, because it wanted to divert spectators away from an area currently experiencing high numbers of cases.
However, it came under fire for the sheer numbers of supporters who attended the match, standing close together.
Sunday's scene's followed criticism after crowds invaded the pitch in Omagh after Dungannon Clarke's won their first Tyrone Football title in 64 years.
Mr McAvoy suggested that it was not necessarily the outdoor scenes which had caused the resulting spike in cases.
"Because that hasn't happened throughout our games from July, it probably relates to activities that happened after the match.
"It tends to relate to possibly some sort of celebration at indoor venues."
He insisted inter-county competition, which starts on October 17 is "a different situation".
"You have central responsibility be it at national level or provincial level for the organisation of those competitions and you're dealing with the elite player in each of those.
"It's a very different dynamic to the club situation.
"We would be hopeful that those competitions will be able to continue, albeit within not only GAA protocols but public health protocols."
It is developing a rapid testing system for players in an effort to keep the competition going.
