Norihiko Akagi. [File photo]

Chief Cabinet Secretary Yasuhisa Shiozaki told reporters Akagi had tendered his resignation, and that it was accepted.

Akagi had been hit by an embarrassing accounting scandal widely viewed as one reason the ruling Liberal Democrats suffered a devastating defeat in Sunday's election.

The Democrats won a landslide, emerging as the top party in the upper house of parliament for the first time ever.

Criticism had been growing against Prime Minister Shinzo Abe's administration.

Akagi is suspected of reporting $730,000 in office expenses over the past decade for a political office that was registered at his parents' address and was defunct.

Akagi took office in June, replacing his predecessor, who committed suicide following money and bribery scandals. Akagi had denied any wrongdoing.