Tokyo police sent papers to prosecutors concerning a suspected threat uttered by a political party leader against an assemblyman who left the party, which opposes Japan Broadcasting Corp. (NHK), sources said.

Upper House member Takashi Tachibana, head of NHK Kara Kokumin wo Mamoru To (party to protect the public from NHK), denied that his actions constituted a threat.

Tachibana, 52, said in a video posted on YouTube on Oct. 2 that he would resign as a lawmaker if he is convicted in the matter.

The allegations stem from a video he posted on YouTube in early July. In it, Tachibana criticized an assembly member of Tokyo’s Chuo Ward who left the party, which is called N-Koku for short.

N-Koku had backed the assemblyman when he won the seat in the unified local elections in April.

“We are going to completely destroy his life,” Tachibana said in the video, according to sources. He also referred to the assemblyman’s family members.

In August, the assemblyman reported the video to police.

Police have examined the video and questioned Tachibana several times on a voluntary basis.

N-Koku stunned the political world by winning a Diet seat in the Upper House election in July. 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.

He also came under fire over a video posted on YouTube in September on how to solve the problem of overpopulation. He suggested practicing “genocide against a race that reproduces like an idiot.”