North Wales Police (NWP) say they are investigating a "number of breaches" of lockdown rules following a friendly between Cefn Druids and Airbus UK.
Cymru Premier side Druids hosted Airbus last Saturday at the Rock in Rhosymedre.
Druids say they have been accused of holding "a social gathering of 20-30 people on a licensed premises".
Club chairman Des Williams has accused NWP of taking a "heavy-handed" approach.
"Officers responded to a report of number of breaches of Covid regulations following a football match in Cefn Mawr on Saturday afternoon," a NWP spokesperson said.
"A prosecution file is being prepared in relation to these breaches and suspected licensing offences and as such it would inappropriate comment further at stage."
Airbus' visit was a warm-up game for Druids as they prepare to return to competitive action on 6 March - they host Barry Town United - after the Cymru Premier's elite status was reinstated.
Druids said police officers arrived at their Rhosymedre clubhouse and accused them of holding the social gathering.
In a statement, Druids said their clubhouse was being used as a changing room for a match that was conducted under the Football Association of Wales' (FAW) elite status banner.
They say players were "getting changed, eating pizza and drinking water and soft drinks" after the game.
The FAW has also been contacted for comment.
The Druids statement added: "No alcohol was served, or purchased and no licensing laws broken because the bar has no alcohol in it.
"The pumps are turned off and the room isn't used owing to Covid restrictions
"The North Wales Police officers made it clear that, despite the FAW 's insistence that we use the clubhouse bar area as a changing room, they deem it against the coronavirus guidelines and therefore the Welsh government policy."
Druids chairman Des Williams added: "I personally support all the efforts of the North Wales Police and understand that they were simply carrying out their duties to protect the public.
"We have compiled with every request and answered every question they asked and will continue to do so, but the heavy-handed way that they set about the club was completely unnecessary and uncalled for."