The prosecutors' recent decision not to indict former economy minister Akira Amari and his aides for suspected graft only highlights the shortcomings of the law to punish lawmakers and their staff for gaining financial benefits in exchange for using their political influence to provide favors. The suspicions surrounding the veteran Liberal Democratic Party lawmaker who once was a key member of the administration of Prime Minister Shinzo Abe make a case for amending the anti-graft law, which has never been applied to Diet members since it took effect in 2001, to give it more teeth.

An explanation by Amari himself about the suspicions is also long overdue. For more than four months since he promised to look more closely into the matter and publicly report the outcome during the news conference announcing his resignation from the Cabinet post, he stayed out of the Diet and the public, citing what he called health problems due to a sleeping disorder, until he faced reporters on Monday — and said he has asked his lawyers to resume the probe into the case, while reiterating denial of his own involvement in any wrongdoing. He should not consider the case closed with the prosecutors' decision.

The Tokyo Public Prosecutor's Office last week dropped the graft charges against Amari and his former secretaries that they had received millions of yen from a construction company in exchange for using their influence to favor the firm in its talks with the government-funded public housing corporation over financial compensation. They were also cleared of the charge that they violated Political Funds Control Law for failing to report a portion of the money they had received from the firm in Chiba Prefecture in 2013 and 2014.