Japan's Defense Minister Tomomi Inada attends a lower house budget committee session at the parliament in Tokyo, Japan July 24, 2017. REUTERS/Toru Hanai

TOKYO (Reuters) - Japanese Defence Minister Tomomi Inada will resign, broadcaster NHK said on Thursday, after a series of missteps, gaffes and a suspected coverup that critics say contributed to a plunge in Prime Minister Shinzo Abe’s support.

Inada, a conservative protege of Abe who was once floated as his possible successor, had already been expected to be replaced in a cabinet reshuffle planned for next month.

Inada in March launched a probe into media reports that defense officials had tried to hide logs showing worsening security in South Sudan, where Japanese troops were taking part in a U.N.-led peacekeeping operation. She has denied reports she was directly involved in the coverup.