Renho, leader of Japan's biggest opposition party, took the unusual step to disclose parts of her family registry Tuesday to prove she has resolved her dual nationality status, a controversial move that critics say could justify future calls for disclosures targeting minorities.

Under the current law, dual nationals in Japan are obliged to choose one over the other by the time they turn 22. The former anchorwoman-turned-politician was born to a Japanese mother and a Taiwanese father.

As an opposition leader, "I'm in a position to demand the current administration right its wrongs and fully account for its actions. But I thought my words would continue to sound hollow if I failed to dispel public misgivings about what I say" about the dual nationality issue, Renho, head of the Democratic Party, told a news conference Tuesday.