Some people that attended the Lamonts' holiday gathering earlier this month tested positive for Covid-19, according to the governor's director of communications, Max Reiss.
Reiss said the event was held at their private residence in Greenwich on Dec. 11.
All guests had to provide proof of full vaccination and present a negative Covid-19 test result before attending, according to Reiss.
A week after the gathering, the Lamonts were notified that a "small number" of guests had tested positive for coronavirus.
Reiss said the governor and first lady test regularly and have tested negative in each instance since the event.
In a statement, Reiss told NBC Connecticut that the governor has had a full slate of public events, including some large gatherings before, during and after their holiday gathering. This includes several events with hundreds of people in attendance, he said.
Lamont continues to urge everyone to get vaccinated and get their booster shots.
Reiss said the governor has more confidence in events he attends where he knows the vast majority of attendees are people who are vaccinated.
The governor recently rolled out the digital health record, or passport, for residents to have additional peace of mind, Reiss said.