Premier League chief executive Richard Scudamore is facing increasing pressure on his position after principal sponsor Barclays expressed concerns to the league over the sexist emails he sent to a lawyer friend.
It is understood that Barclays expressed disappointment to the league this week, and Edward Lord, an equality campaigner who is a member of the Football Association's inclusion advisory board (IAB), has suggested Scudamore's position is "untenable". Meanwhile the lawyer at the centre of the case is facing an investigation from his firm.
DLA Piper, a global law firm with headquarters in London, released a statement after TV rights legal specialist Nick West was named as the person exchanging the emails with Scudamore.
The statement from DLA Piper said: "We uphold the highest professional standards as a firm and this matter is being fully investigated."
The emails, which have been described by FA chairman Greg Dyke as "totally inappropriate", referred to women in a derogatory terms, contained sexual innuendoes, and made jokes about "female irrationality".
The league would not comment on Friday on the latest developments but the involvement of Barclays raises the stakes ahead of a meeting of the Premier League's audit and remuneration committee, chaired by Chelsea chairman Bruce Buck, on Monday to discuss the case, which will also be the subject of a special meeting of the IAB on Tuesday.
After the story broke in the Sunday Mirror, Scudamore issued a statement apologising for the emails, which were sent from his Premier League email account and seen by a former temporary PA who leaked them to the newspaper.
In that statement, Scudamore said the exchanges were "private emails exchanged between colleagues and friends of many years" that should not have been accessed by the temporary employee, but accepted they were inappropriate and added: "It was an error of judgment that I will not make again".
However, an email from Scudamore sent to club chiefs just before the Sunday Mirror's publication has also become public. In it he states the story has "been obviously timed for our last day for it to cause maximum embarrassment to me and therefore the Premier League. The newspaper is asserting that some of the content is sexist and inappropriate. You will be the judge."
That has prompted Lord, who also chairs the London FA Inclusion Advisory Group, to question Scudamore's position.
Lord said on his blog: "This seeming refusal to accept that the content of his emails were in fact sexist and inappropriate to my mind completely undermines his public apology, and leads to only one conclusion: that it was insincere and therefore unsustainable in the court of public opinion.
"If it is that Richard Scudamore didn't believe that what he had written was wrong less than a week ago, I think that it is highly unlikely that he has come to that conclusion in any reality since. On that basis it appears to me that his position is now looking untenable.
"If Scudamore doesn't accept the heinous nature of his sexist remarks and the impact they have had, not only on women in the game, but on the perception they create of football's commitment to equality and inclusion in general, then regrettably I must reach the conclusion that he may be in the wrong job."
Sports minister Helen Grant has already branded the content of Scudamore's emails "completely unacceptable" while Labour's shadow sports minister Clive Efford wrote to both the FA and Premier League asking why Scudamore has not faced action.
Efford has received a response from acting Premier League chairman Peter McCormick saying a process is underway, but the shadow minister said he is concerned the league may take legal action against the woman who leaked the emails.
McCormick's letter says there are "complex legal issues" between the league and the Sunday Mirror "relating to how confidential information including commercially sensitive information was accessed and forwarded".
Efford told the Press Association: "There is a role for whistleblowers in public life and what has been published shows she was right to make these emails public, as this is a matter of public concern.
"If the league take legal action against her that would be outrageous."
England and Everton women's goalkeeper Rachel Brown-Finnis said the emails were an "insult to all women" and that Scudamore should be sanctioned.
She told BBC Sport: "It's not just about women who are involved in football, it was an insult to all women.
"However jokey he was trying to be with that, it's just totally unacceptable in this day and age.
"It's zero defence for me. Private emails when are you head of the Premier League don't really exist.
"Is a sorry enough? Probably not, but I do think the way to move forward is for the Premier League to follow their protocols just like they would with other employees and I'm sure they have policies which would sanction him appropriately for his misconduct."