The former chief of Australia's own anti-doping authority has poured cold water on Jarryd Hayne's new dream of playing Rugby 7s for Fiji at the Rio Olympics.

Former ASADA boss Richard Ings responded to news Hayne had quit the NFL to join the Fiji camp as early as this week ahead of the London Sevens by questioning his eligibility to even play.

Ings stated Hayne would be unlikely to play any professional sport, including rugby sevens, for at least six months pending time spent in a registered drug-testing pool.

The NFL does not comply with the world anti-doping agency's code, meaning any player looking to switch from American football must first undergo intense drug screening before being deemed able to play professional sport elsewhere.


Ings said this morning he expected World Rugby Sevens to step in and veto Hayne's Rio bid.

"The six-month return to competition rule is standard across most sports for athletes returning to international competition. And necessary," Ings said on Twitter.

"If Jarryd Hayne had been playing in WADA-compliant sport he would have grounds to reduce the 6 months.

"But NFL is (performance enhancing drugs) badlands. No chance."

Ings first made headlines as a 22-year-old tennis umpire who took on John McEnroe.

He was ASADA's inaugural chief executive and chairman following its creation in 2006 to replace the Australian Sports Drug Agency.
But the federal government replaced Ings in 2010 amidst talk of mistrust and in-fighting within ASADA ranks.

Hayne and World Rugby are yet to respond to Ings' tweets.

Fiji's coach Ben Ryan also says that Hayne's place in the 12-man Olympic squad is not guaranteed.

"I have no promises he is going to make the 12, but we will see how he goes," Ryan told the World Rugby website.

"He will then come into Fijian camp for the Olympic period. It is a huge challenge for Jarryd but if he gets into the squad it is only going to be on form, because he is a blinding rugby player. If he doesn't make it, is just shows how good this Fijian sevens side is."