The 28-year-old West Australian was overlooked when Shooting Australia moved a quota position to the women's skeet and instead preferred 16-year-old Victorian Aislin Jones as Australia's sole representative in Brazil.

Her non-selection followed a fall-out with national shotgun coach and selector Valeriy Timokhin last year that led to the pair entering into mediation.

A shattered Coles, who also lost an appeal on her Rio omission, opted against a further appeal to the Court of Arbitration for Sport – as teenager Mitchell Iles has done to contest his non-selection for the men's trap – but is now weighing up applying to the AHRC.

"I know it will not change me not going to Rio, but the selection policy that is in place ahead of the Tokyo Olympics [2020] will be a major factor in whether I decide to continue competing until then," Coles said.

The Glasgow 2014 Commonwealth Games champion believes she was discriminated against – a claim that Shooting Australia contests – because Jones' scores and results in junior events counted towards the data used by the selection panel.

Coles agrees with former Olympic champion Russell Mark that Shooting Australia's "sole discretion" selection policy, adopted after the London Games, is damaging the sport, saying it was "open to abuse".

"In the last year my world ranking was as high as 12," Coles said. "The girl they're sending does not even have a world ranking and has never competed at an open ISSF World Cup or world championships. The scores that have got her across the line were actually her junior scores, scored at non-open junior events.

"I believe the process they've used is really discriminating based on age."

Shooting Australia's selection criteria allowed athletes to qualify automatically for Rio if they shot a benchmark score in the process of winning one of two events: the national championships in Brisbane in January and the Australia Cup 2 in Sydney in March. But only one shotgun shooter, Brisbane's Paul Adams in men's skeet, achieved that, leaving the rest of the team to be chosen by a panel.

Coles' dispute with Timokhin stemmed from a World Cup event in Al Ain in the United Arab Emirates last year where she said she felt "abandoned" after the coach didn't sit in his appointed seat behind her for the final, but instead watched from the grandstand. She later reported the issue to Shooting Australia's high-performance boss Tim Mahon, who conducted mediation between the pair.

Fairfax Media contacted Timokhin in Brazil, where he was attending a World Cup competition, but he said he was unavailable to speak on the matter.

Shooting Australia's chief executive Damien Marangon, however, defended the selection committee and denied any suggestion that Coles' problems with the coach, one of three Olympic selectors, contributed to her being left out.

"The Shooting Australia selection panel is chaired by a former chief magistrate [of South Australia, Kelvyn Prescott]. So for anyone to insinuate that people were chosen because they were favourites or because of friendships or relationships is ridiculous," Marangon said.

"It is not fair that the integrity of that panel is being questioned."

The crux of Coles and Mark's argument against the selection policy is that it should return to being principally score-based, rather than weighing placings at events heavily into account . "It's not a subjective sport like gymnastics or dressage. Either you hit the target or you don't," Coles said.

Marangon said all scores, results and head-to-head performances were taken into account by the selection committee from January 1, 2015, to March 6, 2016, explaining that the criteria had changed post-London to accommodate a significant change of competition rules.

"It didn't preclude junior scores and the reason it didn't is because there were occasions – and in this specific occasion – where junior athletes were stopped from competing in senior events," he said.

"The shift in policy from London was needed because the previous policy did not take into consideration semi-finals or finals performances. It only looked at qualifying scores. Under the [Australian Sports Commission's] Winning Edge policy, we are expected to deliver at events that matter, and the shift in policy also aligned with the shift in rules with the ISSF, and that is: post the London Olympics, qualifying scores were no longer counted in any of the finals. You used to carry your score in [to the final]; now, you don't.

"In shotgun events, a lot of the general public wouldn't know that in finals you only can shoot single barrel. It actually becomes a really different event, so you need an athlete that can do both."