NORTH Melbourne is co-operating with the AFL as the league investigates an incident that saw the Sydney Swans field 19 players during the final minutes of Sunday’s draw at Telstra Dome.

Swans ruckman Darren Jolly played about 30 seconds after the man supposed to replace him, Jesse White, ran onto the ground. During that period Jolly won a handball in a passage of play that finished with skipper Brett Kirk kicking the match-tying point.

North coach Dean Laidley said on Tuesday morning the exact circumstances of the incident had yet to be established, but he hoped the matter could be resolved “within the next few hours”.

“What we’ve got to determine is, is Darren Jolly the spare player? Is Jesse White the spare player? Is [Lewis] Roberts Thomson the spare player? Is Kieren Jack the spare player in those final hectic minutes?

“And I think that's what the AFL has to determine.

“We’re working as closely as possible with the AFL at the moment. We’ve given them all the information that we possibly can in regard to the hectic final minute and a half.

“And we’ll help them as far as we can into the investigation.”

When asked what the “right result” was, Laidley said, “We don’t make the decision. [The AFL] are the ones that have got to make the decision.

“We’ve gone back and looked at the video, probably second by second for the last couple of minutes. We’ve got people at the AFL that are going through the whole thing with them."

Laidley said although captain Adam Simpson would have had the option of calling for a head count had he been alerted in time, he doubts whether the Kangas would have issued such an order.

“You can do that sort of thing but I don’t think I’d do it,” he said.

“We think … it was only a short period of time [that the Swans had an extra player on the field].

“And there was other things going on that were probably a little bit more important. We’re actually trying to win the game, not put our hand up and say, ‘Oh, can you please count the opposition players?’ because we’ll win the game that way.”

However Laidley believes this latest saga has highlighted a need to review the AFL’s laws, which currently stipulate that the only way a team can be punished is for an opposing captain to call for a head count.

“Look, there’s no doubt when these sorts of things happen, everything’s going to get reviewed and in the end we’ll get it right,” he said.

“And I think that’s all that everyone’s looking for.”

On Monday night the AFL confirmed it will issue a "please explain" to the Swans, after identifying the error.

"The AFL can confirm that the emergency umpire and interchange steward notified us of this after the game and we have sought an explanation from the Swans," football operations manager Adrian Anderson told Channel Nine’s Footy Classified program.

North CEO Eugene Arocca told the program the club was not initially concerned about the incident.

"I'm not convinced it would not have affected the result of the game either way and we are happy to leave it in the hands of the AFL," Arocca said.

Under AFL legislation, a club captain must call for a count of heads during the time of the offence in order for a result to be changed.