NRL to review Lewis medal voting system

But who polled what will remain a secret, with chief executive Todd Greenberg saying it wouldn't be "fair" on judges Mal Meninga, Darren Lockyer and Laurie Daley to reveal their votes.

Slater became the first player to claim the medal from the losing side of an Origin series when he was awarded the honour after Queensland's game three win on Wednesday.

Slater was out injured in the opener but was arguably the Maroons' best upon his return in game two and again in the final match.

Meninga, Lockyer and Daley voted on a 4-3-2-1 basis for their best players in each game but it seems the even spread of contributors in the NSW team counted against the series winners.

Even Greenberg admitted he was "surprised" that Slater emerged triumphant.

"The way it's described to me is there was a stand-out performer in one side, being Queensland, which is Billy Slater who collected a number of votes," Greenberg told reporters on Thursday in Brisbane.

"And in NSW votes were spread among multiple players who performed well across the series."

Asked if the outcome highlighted shortcomings in the system, Greenberg said: "Potentially, yes. Which is why if we have to review it, we'll have a look at it.

"If there's a better system we can look at, we're always open to it. We review everything at the end of an Origin series, so I'm sure that will be part of it.

"But what you can't question is the integrity of the three people making the decision, and you can't question the capacity they have to judge that themselves as three people who played the game at the highest level."

However, Greenberg said the NRL would not disclose their votes, with the judges all signing confidentiality agreements.

"I don't think it's fair on them to go back and ask them to disclose who they voted for or how they voted," he said.

"I don't think that happens in any medium that I've seen. We don't do it for the Dally Ms, we don't do it for other awards, why would we do it for this?"

Told that full voting details were released by the AFL on grand final day when the Norm Smith medal is awarded, Greenberg said: "That's their sport; our sport, we don't do that, we haven't done it previously and we don't intend to do it today."

NSW coach Brad Fittler suggested Slater may have received the medal in recognition of his achievements in an Origin career dating back 15 years.

"I can live with him taking away a medal but it was more than for this series," Fittler said.

Asked who he thought deserved it, Fittler said: "Tom Trbojevic was pretty outstanding I thought across the three games. He was my pick."

Australian Associated Press