(Reuters) - Singapore Post appointed Isaac Mah, the current CFO of its Australia business, as group finance chief, the company said on Sunday, a week after dismissing three senior executives, including its CFO, over mishandling a whistleblower report.

Mah, who joined Singapore Post in 2019, most recently oversaw the sale of the Australian business to private equity firm Pacific Equity Partners.

Singapore Post fired group CFO Vincent Yik last week, along with CEO Vincent Phang and the chief of its international business unit (IBU), Li Yu, after they were found to be "negligent" in handling a whistleblower report.

The alleged misconduct reported by the whistleblower related to several employees who worked in the company's international e-commerce logistics parcels business.

Singapore Post also said Gan Heng would step up as acting CEO of the international business unit from his current role as head of the South district of the unit.

The Temasek-backed company said it would name a new group CEO "in due course".