The 52-year-old Scot resigned from his post as Blues supremo on Sunday, although that decision was rejected by the St. Andrews board earlier this week.
Villa are reported to have made enquiries over McLeish's availability to succeed Gerard Houllier, who was relieved of his duties following a heart scare last month, but insist it was not an official approach.
And Birmingham's acting chairman Peter Pannu has confirmed that they will be reporting the incident to the Premier League as well as pursuing £5.4 million in compensation, should McLeish seal a move to Villa Park before the end of the month.
"I got an email from Aston Villa, finally replying to all of our queries," Pannu told Skysports.com.
"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 £5.4 million.
"The first year expires on June 30. The second year starts July 1, when the compensation fee is £3 million.
"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.
"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."
Odds on the former Rangers boss taking the reins at Villa Park have been slashed to as little 1/2 with some bookmakers.
By James Martini
