Jarryd Hayne will be eligible to play for the Fiji Sevens in London, World Rugby confirmed overnight.
There were question marks raised by former ASADA chief on Tuesday that Hayne wouldn't be able to be part of the sport's dug testing policy for long enough, after his bombshell code switch.
Despite coming from the NFL, which is not a part of the WADA code, World Rugby said in a statement that players aren't required to be part of a testing pool for a specific period.
Hayne's tick of approval comes after a similar situation with the USA team, with former New England Patriots player Nate Ebner playing just one month after switching sports.
As long as Hayne makes it through all the other eligibility requirements, there will be nothing stopping him from playing in London this weekend.
While he is clear to head to London, Hayne evaded questions about returning to the NRL, saying he's "just taking baby steps" after quitting the NFL in the US to seek a rugby sevens Olympics berth with Fiji.
World Rugby has also confirmed the former Eels superstar will not be barred from Rio contention by drug testing rules.
Hayne told reporters in London on Monday he had "a big mountain to climb" but would work hard for a place under Fiji coach Ben Ryan, and a spot in this weekend's international comp in the British capital.
Hayne's surprise announcement on Sunday that he was leaving the San Francisco 49ers to seek a Rio berth with Fiji has sparked speculation about the 28-year-old's return to the NRL, or a shift to non-sevens rugby.
He said he had made his decision to leave the NFL on Friday after receiving his Fijian passport.
His allegiance was to both Australia and Fiji the 28-year-old told reporters.
When asked if he had considered a return to the NRL and which team he might join, Hayne repeated the phrase "just taking baby steps at the moment".
Hayne has not played sevens rugby before but said he had been in touch with friends for advice about making the transition.
"The biggest thing will be a lot more running that's something I'm looking forward to."
Hayne said he hadn't thought about what he would do if he didn't make the cut for the Olympics with sevens champions Fiji.
When asked why Fiji was keen to take on a star player like Hayne when the side were already champions, coach Ben Ryan told reporters "if you are good, you want to get better".
Ryan cut the press conference short on Monday, accusing media of being rude to a security guard who interrupted the interview to order journalists to move only two metres back.
Hayne's eligibility could make Australia's London Sevens campaign very interesting, with the Aussies drawn to play Fiji in their pool matches.