Members of the Liberal Democratic Party are explaining themselves to a lower-house ethics panel amid a political funding scandal rocking the senior partner in Japan's ruling coalition. LDP leader Prime Minister Kishida Fumio has become the first sitting prime minister to take part.

Kishida told the panel, "As LDP president, I sincerely apologize for the fact that issues involving the political funds of LDP factions have caused the public to have so much mistrust in politics."

The panel is also hearing from five other LDP lawmakers. All are former senior members of influential party factions.

The panel is looking into allegations that dozens of LDP lawmakers failed to properly declare revenue from fundraisers and received kickbacks.

Most of those lawmakers belonged to a faction that used to be led by late Prime Minister Abe Shinzo.

Former Prime Minister Noda Yoshihiko spoke on behalf of the biggest opposition party, the Constitutional Democratic Party of Japan. He said all lawmakers involved in the scandal bear grave political responsibility. He urged Kishida to exercise leadership and hold them accountable.

Noda said, "This will all happen again if they get away without criminal charges, without being held responsible, without having to explain themselves, without paying taxes, without being punished -- in other words, if nothing happens to them."

Kishida said, "The party will decide how those involved should take political responsibility, including being punished. We'll take into account how they honor their responsibility to explain themselves and what the facts are."

Kishida said he is committed to thoroughly reforming his party to regain the public's trust in politics.