Sam Allardyce is "absolutely distraught" over the end of his brief tenure as England manager, says Football Association (FA) chief executive Martin Glenn.
Glenn and FA chairman Greg Clarke met with Allardyce on Tuesday, terminating the 61-year-old's 67-day reign by mutual agreement following allegations published by the Daily Telegraph.
The newspaper alleged Allardyce told two undercover reporters posing as investors based in the Far East how they might "get around" FA rules regarding the transfer of players under third-party ownership.
Video footage released by the Telegraph also showed Allardyce apparently criticising his immediate predecessor Roy Hodgson and assistant Gary Neville, along with the FA's costly rebuild of Wembley.
Additionally, it is also claimed he used his role to negotiate an agreement worth £400,000 to represent the fictitious Far East firm as a keynote speaker at selected events, while stipulating this would be subject to FA approval.
"It's been a really painful decision because obviously we've only just hired Sam, and Sam we think is a great fit for England manager and we think could have been extremely successful," Glenn told the FA's official website, after England Under-21 boss Gareth Southgate was confirmed as Allardyce's successor for the final four games of 2016.
"But the FA is more than just running the England men's team. We have to stand up for the right behaviours across the whole game.
"We are the guardians of the game - we set the rules and we have to be seen to apply those rules consistently and evenly, whether you are the England manager or someone low down in the organisation.
"That consistency, that trust that people have in us to behave in the appropriate manner, is core to what any football association is about and certainly true of the English football association.
"It's a painful decision because we thought he was a great manager, but it's the right decision if we are to protect the integrity of the FA."
Glenn explained former Bolton Wanderers, Newcastle United, Blackburn Rovers, West Ham and Sunderland boss Allardyce had found the quickly escalating chain of events tough to take.
"Sam is absolutely distraught," he said. "He recognises that he made a terrible error of judgement and I think that he recognises as well that, whilst it's a tough decision that the FA is taking, he can see that at least we have a point.
"Once again, I have to say how personally disappointed I am. I thought Sam had already made a big difference to the FA - he came to St. George's Park and showed real leadership there and had clear enthusiasm for the job at hand.
"I know personally that he is deeply, deeply upset and deeply regrets the error of judgement but I also think that he understands why the FA has had to take this tough decision."