The audit, which is due to be published shortly after Building goes to press, is thought to be one reason for Sir Stuart Lipton's decision earlier this week to stand down as chairman. Lipton, who is also chair of developer Stanhope, has spent five years in the role.
The Department for Culture, Media and Sport asked chartered accountant AHL to make an organisational audit of the commission.
The audit is also likely to recommend that the chairman of the design review panel should not be an influential architect.
The current interim chairman is Ken Shuttleworth, the ex-Foster and Partners architect who recently founded the practice Make.
Building understands that AHL will suggest that because CABE's reviews have commercial implications, it is "neither in the public nor CABE's interests that someone with significant commercial interests in the field in which CABE operates should be head of that review".
An individual with a record of unstinting public service across the arts sector
CABE’s Paul Finch on Lipton
In Lipton's case, the potential conflict of interest is that several of the CABE commissioners who review the architectural merits of schemes have worked with Stanhope on projects.
A spokesperson for CABE reacted angrily to the questioning over Lipton's role and the integrity of the commissioners. He said: "Our frustration is that this is a matter of perception. In public life perhaps you need to be bigger than that. It is incredibly important that CABE has people on the commission who are active in their field – why else would anyone listen to them?"
It seems likely, however, that the commission will be made up of more figures from the public sector in future.
A source close to CABE said that Lipton had made the right decision. The source said: "Stuart's interests have changed significantly in his years at CABE, as Stanhope has gone from being a project management company still coming out of a recession to a massive property company."
Lipton said that he had always intended to step down once a new chief executive had been appointed. Richard Simmons was named as Jon Rouse's successor in this role earlier this month.
Lipton added: "I know that I am handing on a mature and high-achieving organisation that will go from strength to strength. I am sure the report's findings will give useful guidance for the future."
Paul Finch, CABE deputy chairman, criticised the pressure placed on Lipton. He said: "An individual with a record of unstinting public service across the arts sector has been caught up in the current fashion for confusing potential, actual and managed conflicts of interest."
There are no plans in place yet for Lipton's successor. CABE was undecided as to whether to appoint an interim chairman ahead of permanent appointment as Building went to press.