The KOC bans athletes who've served doping suspensions from representing the country for three years, starting on the day that their suspensions end. Park, the 2008 Olympic champion in the 400m freestyle, served an 18-month ban that began retroactively in September 2014 and ended in March of this year.

On April 26, Park filed an appeal against the KOC rule at the Court of Arbitration for Sport, the highest sports tribunal.

He later asked the procedure to be put on hold so he could speak to the KOC before taking further legal steps.

Park had been scheduled to meet with the KOC on May 25 but postponed the talks indefinitely without providing a reason. Now that the KOC has rejected Park's plea for reinstatement, the swimmer has asked the CAS to resume its proceedings, Team GMP said.

With Park away in Australia for training, his father, Park In-ho, attended the press conference, saying the KOC was being too harsh.

"I understand where the KOC is coming from, and I also understand the importance of anti-doping," the senior Park said.

"But (Tae-hwan) has already been penalized according to international regulations. I think it's too much to hold one athlete as a scapegoat to emphasize the significance of anti-doping. I ask the KOC to please reconsider its application of its rule."

Despite his Rio ban, Park Tae-hwan chose to compete at the final Olympic trials in April and won the 100m, 200m, 400m and 1,500m freestyle races. He also met the Olympic "A" standards set by FINA, the international swimming governing body, in all four, and his accomplishments put further pressure on the KOC to reinstate Park.

Park In-ho said when his son was first slapped with the doping ban, the Korea Swimming Federation had assured the swimmer that he would be able to compete in Rio after the suspension was over. Yet with the KSF mired in a damaging corruption scandal and coming under the KOC's supervision, the senior Park said, "We've lost our communication channel."

"Tae-hwan did the best he could and met the Olympic qualifying times, but at the end of the day, we've been told that there will be no change to the rule," he said. "Is it right to have an athlete pegged as a drug cheat and force him to live the rest of his life in disgrace?"

Critics of the controversial rule say the KOC is unfairly punishing the swimmer twice for the same offense, and that the principle of double punishment runs counter to international standards.

In 2011, the CAS handed down a decision against the International Olympic Committee's "Osaka Rule," which barred athletes who had served a doping suspension for at least half a year from competing in the following Olympics. The CAS said the Osaka Rule, adopted in 2008, was "a violation of the IOC's own statute and is therefore invalid and unenforceable."

An official in Park's camp said earlier Thursday the CAS has agreed to expedite its ruling by July 8, so that Park would still have a chance to compete in Rio should the tribunal rule in his favor.

The deadline to finalize the national team swimming roster is July 18. Park was left off the preliminary roster announced on May 11.

Lim Sung-woo, an attorney on hand, said he is also reviewing additional legal steps in case the KOC refuses to honor the CAS ruling.

"The KOC rule infringes upon athletes' basic human rights, but the KOC continues to argue it's a valid rule," Lim said. "Given the precedents at the CAS, I don't see any reason why this case should be any different (than earlier rulings), unless the KOC resorts to delaying tactics."

Lim said the CAS ruling will be binding, and those who contend otherwise may be doing so for their lack of legal knowledge. (Yonhap)