England have denied a report that their squad was close to mutiny over a training ground bust-up involving Danny Cipriani and Mike Catt.
It has been confirmed by the World Cup hosts that a flashpoint - described as a "robust conversation" - erupted between the fly-half and attacking skills coach on the day before the squad was announced in August.
Cipriani was disappointed at having learned the previous evening that he was to be omitted from the final 31 after George Ford and Owen Farrell were selected as the playmakers-in-chief.
When the 26-year-old failed to perform a drill in the manner requested by Catt, a row ensued. Press Association Sport understands that Catt twice told Cipriani: "I will end your career".
"Danny and Mike were involved in a robust conversation on the training pitch following a misunderstanding around a training drill instruction," an RFU spokesman said.
"Mike's only intention was only to get the best of the player as he does for all of the players. Both shook hands afterwards."
England crashed out of the World Cup with a 33-13 defeat to Australia at Twickenham on Saturday, in the process becoming the first host nation to fail to reach the quarter-finals.
The fall-out has been predictably brutal as the ruins of a moment being described as the darkest hour in Red Rose history are examined for clues as to why the thinkable has come to pass.
England have offered a robust defence to claims that backs coach Andy Farrell had too much influence over selection and tactics, particular in the recall of his son Owen at the expense of Ford for the critical games against Wales and Australia.
"To say there's a bias in selection is absolutely incorrect and completely unfair on the integrity of Andy Farrell, who I hold in the highest regard," Lancaster said.
"To suggest he would want to promote his son over anyone else is completely untrue and unfair. The ultimate decision on selection always rests with me."
The management's determination to pick Sam Burgess is understood to have been divisive, although opposition over his selection in place of Luther Burrell has been based solely on his lack of union experience.
"I've never had that feedback from any player at all. The boys understand there are tough decisions to make when you're an international coach and accept it's part of the job," Lancaster said.
England's performance is the subject to an internal review by the Rugby Football Union once Saturday's final Pool A match against Uruguay has been played.
The future of Lancaster and his assistants are in grave doubt and the head coach has called for a speedy resolution to the inquest, which he believes should be conducted in an "open, honest and transparent way".