It is understood that the matter relates to a dinner held in the town following a match between Roscommon and Donegal at the weekend.
A dinner held at the premises is reported to have had up to 50 people in attendance.
Under current Level 3 restrictions, no organised indoor gatherings are permitted, while bars, cafes and restaurants are only permitted to serve takeaway food, or offer outdoor dining for a maximum of 15 people.
Hotels, guesthouses and B&Bs can remain open, with "services limited to residents."
According to the Roscommon Herald, Gardaí in the county confirmed "an investigation focused on the organisers of the event is currently underway."
A statement issued by Gardaí read: “Where Gardaí find potential breaches of the public health regulations a file is prepared for the DPP in each case.
“While An Garda Síochána will seek to encourage people to maintain the necessary public health measures, it will intervene where there is non-compliance with public health regulations,” the statement concluded.
Last week, the GAA ordered the suspension of all club games around the country in response to soaring rates of Covid-19 in both Northern Ireland and the Republic.
The inter-county season, due to recommence this weekend, is still expected to go ahead.