Seattle billionaire Chris Hansen says he regrets funding a secretive effort to block a new downtown arena for Sacramento’s professional basketball team.

Hansen’s involvement was disclosed by California’s campaign watchdog Friday.

He issued a statement saying he ”made a mistake” by giving a Los Angeles law firm $100,000. The firm secretly funneled $80,000 to a group gathering signatures to force a public vote on the arena plan.

The Fair Political Practices Commission sued to learn Hansen’s identity.

Reported by the Associated Press