Australian bookmakers face a multi-million-dollar wipeout as North Queensland threaten to pull off the biggest grand final upset in NRL history

Veteran bookmaker Gerard Daffy said the Cowboys were the longest-priced pre-finals underdogs since sports betting was legalised in Australia in 1993

Most agencies had Paul Green’s injury-depleted side at 66-1 to win the title after scraping into eighth spot, with some fans snapping up odds of 100-1 with Betfair.

“They needed miracles to make the eight,” Daffy told AAP on Thursday. “When [Johnathan] Thurston was ruled out for the rest of the season, no one gave them a chance.

“Similar to the AFL’s Western Bulldogs last year, they were $67 heading into finals and big outsiders in each game. But what sets the Cows apart is that they’ve had the big travel each week and defied the odds each week.”

Daffy said UBET had received six times as many bets on the Cowboys than favourites Melbourne, who enter Sunday’s grand final at 4-1 on to win the premiership.

“We are seeing big bets for the Storm but once-a-year league punters are behind the Cows,” Daffy said. “It appears they’ve been adopted by everybody who doesn’t have a side in the finals.

“Those who back them each week are like the side itself: they have nothing to lose. They are playing with the bookies’ money after taking advantage of the three wins and the big odds available.

“If the Cows win, it’ll cost bookies Australia-wide millions. It’s a disastrous result [for bookmakers].”