Josh Adams has been suspended for Wales' Six Nations games against Ireland and Scotland after breaching COVID-19 protocols.
Wayne Pivac's squad were released from their training camp on Saturday and wing Adams attended a gathering the following day, where his immediate family were present.
That breach of the rules came to light when the squad returned for international duty on Tuesday, with Adams missing Wales' first Six Nations game against Ireland at the Principality Stadium on Sunday and the trip to Murrayfield six days later.
Adams said: "I would like to apologise unreservedly. When out of camp, at the weekend, I made an error of judgement. I attended a small gathering of immediate family to celebrate a family milestone.
"It was wrong to do this. I'm aware that everyone needs to follow the rules and being in the public eye I have a responsibility to lead by example and I've fallen short on this occasion.
"I'd like to apologise to my team-mates and to our supporters for my mistake."
Wales head coach Pivac said: "We are extremely disappointed with the breach and have acted robustly and swiftly to take all appropriate measures.
"All players and management have received detailed briefings and education regarding our protocols, and everyone has a responsibility to abide by the rules.
"On this occasion, Josh has made an error of judgement, he made a mistake and he has shown immediate remorse. He was present at a small, immediate family gathering to celebrate a milestone with those close to him but that is against the rules and action had to be taken.
"All members of the national squad have received extensive COVID-19 protocol briefings and education. We will continue with our programme, which has been very effective to date, and remind everyone of their responsibility to not only adhere to the extensive measures in place but also to set an example.
"We will work with Josh in relation to his integration back into camp following a further testing and re-education process."