England’s match against the Barbarians at Twickenham on Sunday has been called off after 12 Barbarians players were stood down for breaking Covid rules.
The players left their hotel bubble – contrary to team protocols – to have dinner at a London restaurant.
During its investigation, the Rugby Football Union (RFU) said it discovered another breach where players left the hotel without permission.
Former England captain Chris Robshaw is among the players who have apologised.
It is understood several Barbarians players went to a central London pub on Tuesday as well as an Italian restaurant on Wednesday.
The RFU said the players’ actions meant the “bubble environment” was compromised.
“We are incredibly disappointed to be calling a halt to this fixture,” said RFU chief executive Bill Sweeney. “We know how much fans were looking forward to seeing the teams play.
“However, our priority is to protect the health and safety of the England squad and the other international teams they will go up against this autumn.”
Robshaw ‘sincerely remorseful’ for breach
Robshaw, Richard Wigglesworth, Sean Maitland and Jackson Wray were among the 12 players stood down from the fixture, along with a number of other Saracens players.
Robshaw, who is set to join San Diego Legion in the US, expressed his “deepest apologies” for “leaving the hotel post-training with some of my team-mates”.
“A huge effort went into conducting this match in a safe fashion and it was irresponsible of me to break the protocols which are put in place to protect players, staff and the public,” he said.
“I understand that my actions have ultimately contributed to the cancellation of Sunday’s match and I am sincerely remorseful for my role in undoing all the amazing work that went into trying to make it happen.
“I promise that I will learn from this mistake and ensure something like this never happens again.”
Former England scrum-half Wigglesworth said: “Embarrassed and beyond gutted to have let (coach) Vern Cotter and everyone at Barbarians FC as well as the RFU.
“Should not have happened and for that I am truly sorry. I’ve let a lot of people down including myself and wish I’d done it differently. Sorry again.”
Saracens lock Joel Kpoku and former Ireland wing Fergus McFadden also posted social media apologies.
The Barbarians, who announced their 23-man squad on Wednesday, were given a 15:00 BST deadline on Friday to attempt to recruit a team.
Premiership Rugby officials emailed clubs on Thursday to ask if they would release players to play for the invitational side.
However, it has now been deemed unsafe to fulfil the fixture.
Sweeney said: “There has been a great deal of effort put into Covid codes of conduct and planning for games, including cooperation with Premiership clubs to release additional players to fulfil the fixture safely.
“We are all incredibly frustrated and disappointed that the actions of a number of Barbarians players mean we no longer feel it is safe for the game to go ahead.”
Barbarian FC expressed their “extreme disappointment” in the conduct of the players who breached regulations.
The build-up to Barbarians games is famous for its focus on socialising and the team management installed a team room in their London base to keep the players entertained.