Details of Fulham's court action against Sir Dave Richards emerged today showing the club has demanded his removal as chairman of the Premier League, or at least a ban from any involvement with transfers, the Guardian can reveal.

The Premier League chief executive, Richard Scudamore, confirmed in an email to all member clubs this week: "Fulham are asking the court to order an injunction restraining the chairman [Richards] from taking any role in the transfer of players or, alternatively, that the court remove the chairman from the board of the Premier League."

It is an extraordinary and unprecedented step from a shareholder club to take recourse to the high court against the chairman, whose role it is to represent their interests as the custodian of his organisation's corporate governance. Fulham's fury was ignited over Richards's involvement in Peter Crouch's transfer from Portsmouth last summer.

According to Scudamore's email, the fact Richards became involved is not in dispute. It states the League ordered an inquiry and found there had been no impropriety on Richards's part. "The inquiry concluded the chairman's actions had not been detrimental to Fulham, and that it was not inappropriate for the chairman to assist in such matters when requested to do so by a club," Scudamore wrote.

However, Fulham are not satisfied by the outcome of the inquiry and on 27 April delivered their petition to the companies court. They maintain their allegation that it was Richards's intervention that prompted Crouch to abandon his pledge to join Fulham, for £11m, in favour of a switch to Spurs, for £2m less.

Though he accepts he did speak with Portsmouth's then chief executive, Peter Storrie – a personal friend – Richards denies he sought to assist Spurs over Fulham.

Scudamore said: "The claim is that Fulham have been unfairly prejudiced in their capacity as a member of the Premier League, as a result of alleged assistance provided by the chairman to Portsmouth in securing the transfer of Peter Crouch to Tottenham Hotspur in August 2009."

Richards maintains Portsmouth, under pressure from HM Revenue & Customs over an eight-figure debt that threatened to push them into administration, sought to receive cash up front.

Spurs' payment to Pompey was indeed in a single lump sum of £9m but it will be for the courts to test how Fulham's offer would have been arranged.

If the courts accede to Fulham's request for the removal of Richards it would be a seismic shift in English football. After 11 years as Premier League chairman, Richards has built arguably the biggest powerbase in the game. The 66-year-old former Sheffield Wednesday chairman is also vice-chairman of the Football Association, chairman of Club England and on the FA's international committee, an array of interests that is attracting increasing scrutiny and would prove untenable if he is toppled at the Premier League.