The Daily Telegraph said it had "confirmed Waerea-Hargreaves had been given word he would collect the medal.
"He lined up near the presentation stage as he waited to be introduced to the crowd. However, he was told moments later that it was in fact Wighton who was voted the winner by Australian selectors Laurie Daley, Mal Meninga and Darren Lockyer."
The correction was apparently only made on stage when NRL chief executive Todd Greenberg told the MC that there was a change.
Reports say Waerea-Hargreaves had to walk "sheepishly" back to his team mates, and that Channel 9 cameras had even been lined up on him.
Waerea-Hargreaves had been the outstanding Roosters forward against a dominant Canberra pack. He made 185 metres – the most for any forward - and 41 tackles.
However, most pundits agree that Wighton deserved the medal despite being on the losing side and some of the crowd booing the announcement.
Wighton said: "It was a very numb feeling to achieve something so big, it was probably the worst moment of my life, losing a grand final."
Raiders coach Ricky Stuart said: "The best player on the field got the award tonight.
"Whether those people out there that booed agree or not, Jack didn't pick it. Three legends of our game pick the award.
"And I think they know a little bit more than the wombats sitting in there beside the goal posts."