The Blues claims do not believe that McLeish is a free agent and that the Scot is contracted to Birmingham City, the St Andrews club will now seek an injunction against their rivals to prevent them joining Aston Villa.
"I got an email from Aston Villa, finally replying to all of our queries," confirmed Pannu.
"As expected, their legal department said 'now Alex McLeish is a free agent having resigned, we're free to speak to him'. This confirms all suspicions. This shows what has happened.
"Within the first year he (McLeish), or the club who sign him, have to compensate us at £5.4m.
"The first year expires on June 30. The second year starts July 1, when the compensation fee is £3m.
"The urgency of the whole thing, with this email from Aston Villa, shows they can't even wait 17 days when the compensation is lower. It shows what this is all about.
Blues' acting chairman, Peter Pannu insists they are entitled to £5.4million should McLeish join Villa this month, although that figure will drop to £3m from the start of July.
"Because of this, what option is left to Alex McLeish and his advisers? To make allegations against Carson Yeung, against the board, for interference or whatever excuse to show constructive dismissal.
"I'll be seeking an injunction preventing Villa from hiring him.
"I'll be reporting what's happened to the Premier League. This is like conspiracy to defraud.
"It's borderline criminal. That's how strong I'll put it."
