The takeovers panel, which last week received an application from Coopers claiming foul play by Lion Nathan, said on Monday that it had since had a declaration of unacceptable circumstances from Lion Nathan.
The brewer of Tooheys, XXXX and Hahn said the Coopers board has made conflicting and misleading statements that are likely to confuse Coopers shareholders about the value of their shares.
Lion Nathan launched a $352 million takeover bid for Coopers earlier this month, offering $260 per Coopers share.
The takeovers panel said it had not decided whether to conduct proceedings on Lion Nathan's application. Nor has it made a decision on the application from Coopers.
Lion Nathan has also lodged an appeal with the full court of the South Australian Supreme Court against a decision to remove its pre-emptive rights to buy Coopers shares.
Under the pre-emptive rights regime struck in 1995, which had been removed by the SA Supreme Court, Lion Nathan was third in line to buy Coopers shares when they came up for sale.
The Coopers board has recommended against accepting Lion Nathan's off-market offer of $260 cash per Coopers share.
Coopers has 117 shareholders and about 1.35 million shares on issue.
It says that more than 50 per cent of the company is in the hands of Coopers directors and their families, with descendants of the Cooper family holding 90 per cent.