A major investor in Molson has queried last week's vote in favour of a merger with Coors. The complaint comes on the same day as Coors' shareholders are voting on the proposed move.

Richard Grubman, a managing director of Highfields Capital Management, a Boston-based investment manager, said his company is contacting the Toronto Stock Exchange and Ontario Securities Commission as he feels that some of Highfields' votes cast against the deal were not counted in last week's vote.

"I consider this a material discrepancy and if it is determined that it is a material discrepancy, they need to go back and re-examine the vote," he told the National Post. "I just want to know what the facts are. If we lost, we lost. But somebody should at least be able to say the votes were counted properly."

Highfields believes that the number of class B share votes against the merger does not tally with the number of shares held by the investment manager and former deputy chairman Ian Molson who also voted against the move.

Molson spokeswoman Sylvia Morin told the National Post: "This is not a Molson issue. It's a voting process and the voting process is in the hands of a third party."

A spokeswoman for transfer agent CIBC Mello Trust told the newspaper: "A vote came in before the (meeting) cut-off date from a participant that had no valid position on our register."

"What we need to have is valid votes and direction or instruction for the vote.... Our role is to tabulate valid votes received. This one wasn't valid and we weren't able to tabulate it."