Japan’s Toshiba Corp on Friday said more than 1,000 postal voting forms for its shareholder meeting went uncounted, while the bank responsible for the counting said the oversight may not have been limited to Toshiba.

The admissions by Toshiba and Sumitomo Mitsui Trust Bank are likely to deepen concerns about corporate governance in Japan at a time of new political leadership and increased scrutiny by investors.

They are also likely to highlight nagging worries about the treatment of foreign activist investors at Toshiba’s contentious July 31 shareholders meeting.

Toshiba said that 1,139 voting forms, representing a combined 1.3% stake, were left out for its annual meeting even though they were delivered before the July 30 deadline to Sumitomo Mitsui Trust, its shareholder registry administrator.

Sumitomo Mitsui Trust said the vote-counting problem may have happened at other clients, because it uses the same vote-counting procedure.

Toshiba said it will continue its investigation and take appropriate action.

Reuters last month reported Singapore-based hedge fund 3D Investment Partners, a major investor in Toshiba, had called for a third-party investigation into the meeting, saying its vote had not been fully recognised.

Toshiba’s subsequent internal investigation found that about 1,300 voting forms, with postmarks indicating they were accepted at post offices close to senders on July 27, failed to be counted for the July 31 shareholder meeting.