Darren "The Gazelle" Hibbert reportedly could be headed to court after the supplement salesman's interview with ASADA was cut short on Friday.
Hibbert is accused of selling illegal peptides to NRL players and is a key person of interest in ASADA's ongoing investigation.
The man dubbed The Gazelle has a long association with sports scientist Stephen Dank and has been linked with the Cronulla and Manly clubs.
Hibbert said he was nervous as he faced investigators at the Australian Crime Commission (ACC) building in Sydney on Friday morning.
However, his interview was cut short after an hour, with reports suggesting Hibbert may face punishment for obstructing the process.
Nine News said he could face a fine, while News Corp Australia reported that Hibbert argued ASADA was in breach of human rights laws by forcing him to be interviewed.
"I think any average person would be nervous going to the ACC building - it's pretty intimidating," Hibbert told Nine News.
"I've got nothing to hide.
"I've never given banned substances to any athlete."
Asked whether he would cooperate with ASADA in the future, Hibbert said: "Yes, I've always said I'd cooperate with them."
Manly coach Geoff Toovey said earlier this week that he was glad Hibbert was being interviewed by ASADA and stood by his belief that the Sea Eagles had nothing to worry about.
The game has been bracing for the NRL to hand down punishments to Cronulla this week over their 2011 supplements program, however so far nothing has happened.
The NRL has said its investigation is still ongoing.
