The Rugby Football Union's governance "is broken", according to a report which a leading RFU official did not originally want to be published.
The BBC has obtained a copy of the report into the sacking of former chief executive John Steele.
Acting chief executive Martyn Thomas, who had initially threatened legal action over the report's publication, is heavily criticised.
His influence is such that Thomas is in a position where "he is the union".
RFU disciplinary officer Judge Jeff Blackett's report identified Thomas as a "major contributor" to leaks causing "reputational damage".
"Sponsors, potential applicants for appointment and people of influence within and outside the game of rugby do not trust the RFU to comply with obligations of confidentiality," concluded report, which is due to be published by 30 September.
"Individual members of the board have acknowledged this and the reputational damage it has caused, but collectively they have closed their eyes to the problem.
"As a result, there are many commentators and people of influence within and outside the game of rugby who believe that governance at the top of the union is broken."
Thomas, who took on the role of chief executive following Steele's departure in June, stood down as chairman in July and survived a vote of no confidence on Friday.
However Blackett's report added: "One man holding too many roles means that there are insufficient checks and balances.
"This not only puts mental and physical pressure on him, but it is also maybe a contributory cause to him inadvertently disclosing confidential matters to unauthorised people - simply because his various roles require him to speak to so many people on so many subjects."
The report recommends "all of the non-executive members of the board (apart from co-opted member Bill Beaumont) should resign from the board."
And BBC Sport understands that Blackett may still charge Thomas with "conduct prejudicial to the interests of the union" under RFU regulation 5.12.
Thomas is in Sicily for a European Rugby Cup meeting and was not immediately available for comment.
The leaking within the RFU was so widespread that Steele "felt unable to work with the board" because of his concern that anything he told the board would be passed to the media.
"We are concerned that the board accepted leaks as part of life and effectively shrugged their collective shoulders," added the report.
In an effort to control the level of leaking from the RFU, the report recommended the organisation's officials must seek clearance from the corporate communications and public affairs director Peter Thomas before speaking to members of the media, although Thomas has subsequently left the union.
Blackett's recommendations for improved RFU governance include the appointment of an independent non-executive director by 31 October 2011 and that the RFU chairman must be non-executive "in the true sense of the term".
"The Board must not allow him to stray into executive matters", said the report.
"Board meetings must be properly managed and the union's legal officer and chairman of governance must guard against allowing decision making 'on the hoof' and without proper consideration."
Newly appointed permanent RFU chairman Paul Murphy wants to contact the organisation's member clubs before providing comment to media on the Blackett report, with his response expected by the end of the week.