Tokyo police have questioned the leader of a political party that opposes Japan Broadcasting Corp. (NHK) about a video that purportedly threatens a local assembly member who left the party.

Takashi Tachibana, head of NHK Kara Kokumin wo Mamoru To (party to protect the public from NHK), acknowledged that he had been questioned, on a voluntary basis, about the video at the Tsukishima Police Station on Sept. 9.

Tachibana posted the video on YouTube in July after an assembly member of Tokyo’s Chuo Ward left the party, which is called N-Koku for short. The assemblyman had been backed by N-Koku when he won the seat in the unified local elections in April.

“We will keep attacking until he resigns as an assembly member,” Tachibana says in the video, which also contained references to the assemblyman’s family members.

At a news conference in the Diet, Tachibana denied any wrongdoing.

“I think there is nothing wrong with it (the video) because he and I are both politicians,” he said.

However, Tachibana said he would resign as a lawmaker if he is indicted, convicted and fined over the matter.

N-Koku stunned the political world in July by winning a Diet seat in the Upper House election. Its rally cry was “destroy NHK,” Japan’s public broadcaster.

Tachibana, a former NHK employee, has proposed scrambling NHK broadcasts so that people who do not watch the public broadcaster’s programs can avoid paying subscription fees.