The report, by City solicitors Linklaters & Paine, has been compiled under "legal privilege", by which testimony from those involved will not be published in return for their co-operation.
This weekend, the board is still haggling over the drafting of the circular.
Wickes sources say new chairman Michael von Brentano is determined to avoid a whitewash.
Legal problems mean, however, that it is still unclear how far top management, including former chairman and chief executive Henry Sweetbaum and operations director Michael Corner will be criticised.
Mr Sweetbaum resigned in June after discovery of more than pounds 50m of overstated profits.
Two other executives, trading director Les Rosenthal and UK commercial director Chris Miles, have been dismissed.
Mr Corner and non-executives close to Mr Sweetbaum remain on the board, though all - including Mr Von Brentano - are expected to go after a pounds 30m refinancing later this year.
Central to the scandal is documentation from suppliers over rebates which misled the auditors, an offence that carries a penalty of up to two years in jail.