Scottish league sponsor Ladbrokes has suspended betting on the new Rangers manager after Alex McLeish was backed to take over.
McLeish has been the favourite with several bookmakers even before Aberdeen boss Derek McInnes insisted he was staying at Pittodrie last week amid ongoing speculation linking him with a return to Ibrox.
Rangers sacked Pedro Caixinha more than a month ago and have lost their last two games under caretaker boss Graeme Murty.
And Ladbrokes reported a series of bets on McLeish being placed in charge for a second spell at Ibrox following Friday's defeat by Premiership bottom club Dundee.
David Macdonald of Ladbrokes said: "Money talks and the bets we've seen suggest Alex Mcleish is on the verge of returning to Rangers."
McLeish was interviewed for the job before Caixinha was appointed in March but lost out and later expressed reservations about some issues which came up in talks with the club.
The former Scotland manager won seven trophies during four-and-a-half years as Rangers manager from December 2001, including two titles. His most recent managerial job was a short stint at Egyptian side Zamalek early last year.