The state's health department said it has identified 18 people who tested positive for the virus after attending the Aug. 7 event at Big Moose Inn Cabins and Campground in Millinocket, about 70 miles north of Bangor.
Another six people who had close contact with those attendees have also tested positive, according to a state press release, adding that all of those infected are Maine residents.
About 65 people in total were at the wedding reception, health officials said in the release.
The inn did not immediately return a request for comment Tuesday.
The health department is continuing to investigate the case, including conducting contact tracing for guests, staff and "people who potentially came in close contact with confirmed cases during and after the event," the release said.
The state is also "communicating with Big Moose Inn about the nature of the event and adherence to State requirements."
The Maine governor's executive orders limit gatherings to 50 people indoors, 100 people outdoors and fewer if the space cannot accommodate five people per 1,000 feet.
As of Monday, Maine had a total of 4,197 coronavirus cases and 127 deaths, according to a state website.
Due to the pandemic, many couples have been forced to either postpone, downscale or in some cases cancel their planned weddings.
This article was originally published on NBCNews.com.