The head of a minor opposition party whose primary goal is to "crush" NHK said Monday he was questioned by police for alleged intimidation.
Takashi Tachibana of NHK Kara Kokumin o Mamoru To (Party to Protect the People from NHK) said he will "not resign immediately" but suggested he would if found guilty.
"There's no problem at all," Tachibana said at a news conference after he was interrogated for an hour.
He confirmed that the police questioned him on suspicion of blackmailing a male member of the municipal assembly in Chuo Ward, Tokyo.
The alleged victim, who won a seat on the party's ticket in April, was expelled in June after a financial problem with the party emerged, a source said.
Tachibana uploaded a YouTube video condemning the man, describing him as a "turncoat" and pressuring him to resign. The man submitted a complaint to the police saying Tachibana threatened him.
The party won its first Diet seat in the Upper House election in July.
Tachibana, a former employee of NHK, is known for making inflammatory remarks on his YouTube channel about TV personalities and those who oppose him.
The party calls for abolishing mandatory payment of subscription fees to NHK, arguing that only those who watch the public broadcaster should have to pay.
The party won around 980,000 votes in the proportional representation system in the July 21 Upper House election.
Tachibana is not the only controversial figure in the party. Hodaka Maruyama became the vice leader after he was expelled from Nippon Ishin no Kai for suggesting Japan should wage war with Russia over disputed islands off Hokkaido.