The Welsh Conservatives have denied that its leader Paul Davies, chief whip Darren Millar were involved in a "second night of drinking" on the Senedd estate.
Political news and gossip website Guido Fawkes reported that the Senedd members returned to the same tearoom on December 9 following the revelation they consumed alcohol along with Labour's Alun Davies and the Conservative's chief of staff Paul Smith the night before.
It has forced the Senedd Commission to investigate that announced on Friday that possible breach of regulations occurred that evening, and the matter has been referred to Cardiff Council and the Standards Commissioner.
All four men have denied breaking Covid-19 rules and say they observed social distancing while meeting to discuss working together on a proposed bill.
In a previously issued statement, Paul Davies, Mr Millar and Mr Smith said they were "profoundly sorry" for their actions.
Fellow Conservative MS Nick Ramsay denied he was part of the group but had attended the tearoom on his own for a meal on December 8.
In a statement following the Guido Fawkes publication, the Welsh Conservatives said, "There was no evening of drinks on either the 8th or the 9th December.
"Self-serve catering arrangements were available for Senedd Members on both 8th and the 9th December. Both Paul Davies and Darren Millar used these on both dates and Nick Ramsay used them on the 8th.
"Any suggestion that there was a drinks party until 2am on the 8th December and that people complained and were pressured into keeping facilities open is wildly inaccurate and untrue.
"The members concerned did not breach coronavirus regulations but have apologised for any negative impression that may have been given.
"They are cooperating fully with an investigation and will continue to do so."
It comes as the Welsh Conservative group gave its unanimous backing to Paul Davies for him to continue in his role as the party's leader.
On Friday, First Minister Mark Drakeford told a press conference in Cardiff that he had "immediately made the decision" to suspend Alun Davies from Welsh Labour's Senedd group after hearing of the allegations on Monday.