Sir Bobby Robson was reportedly considering approaching Leeds for Caldwell's release to cover for the injured Jonathan Woodgate, but officials at Elland Road have heard nothing from The Magpies.
Club secretary Ian Silvester said: "Even if Newcastle were to approach us for Stephen's release it is most unlikely that we would agree.
"There is no clause in the loan agreement allowing him to return before the end of the season without the agreement of all three parties - both clubs and Stephen. I don't think he would want to go back there at this stage anyway."
Club secretary Ian Silvester said: "Even if Newcastle were to approach us for Stephen's release it is most unlikely that we would agree.
"There is no clause in the loan agreement allowing him to return before the end of the season without the agreement of all three parties - both clubs and Stephen. I don't think he would want to go back there at this stage anyway."