New owner Stewart Donald confirmed Sunderland had "agreed terms and the contracts are with the lawyers".
However, St Mirren chairman Gordon Scott has said there has "been no contact from Sunderland".
He said: "Jack is on holiday. So unless there is some major skullduggery going on then it's nonsense.
"To hold talks with Jack, we would have to grant permission, but we've had no contact from Sunderland at all."