Sports Direct tycoon Mike Ashley has criticised Debenhams executives, accusing them of "falsehoods and denials" days after tabling a £150m rescue offer.
The comments are likely to stoke fears the department store chain will go into pre-arranged administration this week.
Mr Ashley is said to have called for the board to be investigated, two members undergo lie detector tests and trading in shares to be suspended.
The retail magnate is reported to have offered the package over the weekend, with attached conditions including that he is made its chief executive.
Debenhams was yet to respond to the offer, but the BBC said a statement released by Sports Direct on Sunday night accused executives of "a sustained programme of falsehoods and denials".
"Misrepresentations were made to induce Sports Direct into signing a non-disclosure agreement, locking them out of any ability to trade in the bonds or equity of Debenhams for a period of time", it added.
Mr Ashley has a near-30% stake in the department store and shareholders are likely to be wiped out if the department store presses on with a £200m refinancing plan announced in March.
Under the plan, £101m is to be drawn down immediately, in order to allow restructuring which will include store closures and rent reductions.
The other £99m would have been made available if Sports Direct – or any other shareholder with a stake of more than 25% – fulfilled one of two conditions by April 8.
One option allowed Mr Ashley to make a takeover offer which included arrangements to refinance the group's debt.
Alternatively, he had to call off an emergency meeting he requested to install himself on the retailer's board and commit to either providing funding for the business or underwriting the issue of new shares.
He is reported to have tabled a last-minute rescue package on Friday which depended on him being made chief executive.
In it, the Newcastle United owner offered to underwrite £150m of new equity funding for the retailer.
However, it also required £148m of debt to be written off by lenders.