An alleged ineligible player could strip this season's Barkly AFL premiers of its maiden flag days after winning a heartstopping grand final in Tennant Creek.

YDU Demons defeated Elliott Hawks in a five-point triumph on Saturday to celebrate a breakthrough men's premiership since one of four Tennant Creek-based sides joined the central Northern Territory competition in 2010.

But in a controversial move, a protest from rival sides – headed by minor premiers Elliott – has been lodged regarding one of YDU's most instrumental players in the club's fight to reach the finals.

Kyle Stuart is alleged to have played for Pioneers Football Club in the Alice Springs-based, Central Australian Football League (CAFL) 12 times throughout the season while also playing for YDU under the name Kyle Walker four times amid CAFL byes, including playing in the Barkly AFL preliminary final.

It is understood it is not entirely against the rules to play for a second club in the same season, however it is also understood that to join a club in another competition, the game's administrators must be told and the player registered under their legal name on the Play HQ online profile.

AFL Northern Territory is currently investigating an allegation that YDU created another account for the player, Kyle Stuart, instead using his middle name as a surname.

Stuart was told he was ineligible to play in Barkly AFL grand final once administrators became aware, however YDU still won the season-deciding clash 8.5 (53) to 6.10 (48) despite his absence.

Days after the match, Hawks coach Wade Nish told National Indigenous Times a decision was made prior to the grand final to play the premiership decider on September 20 as scheduled.

The YDU player had initially played the minimum number of three matches so to qualify for the Barkly AFL finals.

"He had a permit to play for Pioneers in Alice Springs, but you are only allowed one permit per year," Nish said.

The point of contention is whether the player was registered to play for Pioneers and had a seperate permit to also play games for YDU.

Elliott had also lodged its appeal against YDU before the league's grand final.

"We were actually told the investigation would happen after the grand final," he said.

"If they have breached the rules, they will drop down from second on the ladder before the finals to about sixth on the ladder."

Elliott, which is situated 250 kilometres north of Tennant where four of the eight Barkly AFL clubs are located, was aiming to win its third premiership in succession.

Despite his club's protest, Nish admitted to having some sympathy for YDU attempting to break its premiership drought.

However he staunchly defended the club's right to contest the grand final result on behalf of the competition's six clubs, despite being the clear beneficiary of the outcome.

"They have been trying for nearly 20 years it feels, which it would have been great, but there are other teams that could have qualified for the grand final then," Nish said.

"They all were pretty upset and they said I should not have played the grand final – and we should have gone out there, just to walk off the field and say we're not playing."

Elliott was expecting an outcome on the decision on Thursday afternoon of whether the club would claim its sixth premiership, however the verdict has been postponed until next week to ensure both clubs can be properly represented at a hearing in Darwin.

Nish believed the premiership should be taken away from YDU to set a precedent regarding unregistered player movement.

"All the clubs now knowing if they get away with that, well, then what is to say no one else will do it too?" he said.

Elliott flew out of the blocks on Saturday to kick 3.4 to one goal straight in the first quarter, however YDU took control after the quarter-time break to score four goals to three behinds in the second term and 2.3 to 1.1 in the third to blow the margin out to 13 points at the last change.

YDU, with Walker playing, proved too strong for Barkly Work Camp 12.6 (78) to 7.5 (47) in the preliminary final the week before.

Sporties Spitfires defeated Elliott 7.7 (49) to 4.2 (26) in the women's grand final before the men's fixture on Purkiss Reserve.

Soaping Bore snared the Barkly Division 2 Community grand final 6.7 (43) to 6.5 (41) against Ampilatwatja.

National Indigenous Times contacted AFL Northern Territory and YDU coach Llewelyn Morrison for comment.