"They took our phones away, we didn't know why," said Wighton, a shock winner over Nathan Cleary.
Panthers chairman Dave O'Neill said the club was upset that Nathan Cleary had effectively wasted his time during grand finals week.
"We want to wish Jack (Wighton) the best," he said.
"It's disappointing that Nathan, in the busiest week of his career, had to travel from Penrith to Artarmon and sit there at the Dally M knowing that he's not going to win it."
ARL commission chairman Peter V'landys said an investigation would be launched, and the media was unlikely to receive embargoed results again.
Adding to the embarrassment, the Dally M awards are run by Fox Sports, who - like the Telegraph - is owned by News Corp.
Wighton also won last year's grand final Clive Churchill Medal in controversial fashion, after Roosters prop Jared Waerea-Hargreaves was told he had won.
The Dally M result went down to the final round with Wighton, Parramatta captain Clint Gutherson and Cleary all within two points of the award.
Cleary was strongly favoured to come away with the win ahead of leading his Penrith side into the Grand Final against the Melbourne Storm, but Wighton pulled off the major upset.
"I can't really explain, I'm actually speechless," Wighton said. "Coming here tonight with these guys, I really didn't think I was going to walk away with this award. I don't know what to say."
Wighton praised coach Ricky Stuart for the "faith he showed to move into the halves after lighting up the NRL as a fullback when he first emerged on the scene.
As a proud Wiradjuri man, Wighton was asked what he thought winning the NRL's highest honour meant for First Nations people.
"I always try to be a leader and role model to all the younger kids and just show them and set the example that whatever they put their best foot forward to, they can try and achieve," he said. " I just try to look at it like that."
New Zealand Warriors skipper Roger Tuivasa-Sheck was captain of the year while teammate Tohu Harris was named in the team of the year. The Warriors club was also awarded the Provan Summons medal to acknowledge their sacrifices in a bid to keep the game going through the disruption of COVID-19.
In awkward scenes, the result was accidentally leaked before the count with Wighton coming home strong to reach 26 points.
Fans were quick to say Cleary was "robbed" after guiding his side to 17 straight wins as he established himself as one of the stars of the league.
The NRL also revealed a full team of the year with 13 players selected
TEAM OF THE YEAR
Fullback: Clint Gutherson (Eels)
Wings: David Nofoaluma (Tigers) and Josh Addo-Carr (Storm)
Centres: Kotoni Staggs (Broncos) and Stephen Crichton (Panthers)
Five-Eighth: Jack Wighton (Raiders)
Halfback: Nathan Cleary (Panthers)
Props: Josh Papalii (Raiders) and James Fisher-Harris (Panthers)
Hooker: Cameron Smith (Storm)
Second rowers: Viliame Kikau (Panthers) and Tohu Harris (Warriors)
Lock: Isaah Yeo (Panthers)
THE AWARDS
Dally M Player of the Year: Jack Wighton (Raiders)
Dally M Female Player of the Year: Ali Brigginshaw (Broncos)
Coach of the Year: Ivan Cleary (Panthers)
Provan Summons: New Zealand Warriors
Top Pointscorer: Adam Reynolds (Rabbitohs)
Rookie of the Year: Harry Grant (Tigers)
Ken Irvine Medalist (Highest tryscorer): Alex Johnston (Rabbitohs)
Peter Frilingos Headline Moment of the Year: Project Apollo
Captain of the Year: Roger Tuivasa-Sheck (Warriors)
NRLW Rookie of the Year: Kennedy Cherrington (Roosters)
NRLW Try of the Year: Madison Bartlett (Warriors)
NRLW Tackle of the Year: Hannah Southwell (Roosters)
VB Hard Earned Player of the Year Award: Jake Trbojevic (Sea Eagles) and Tohu Harris (Warriors)
Try of the Year: Kotoni Staggs (Broncos)
Tackle of the Year: Josh Papalii (Raiders).
- With news.com.au
