Singapore Post chief operating officer Sascha Hower has quit, the latest in a series of departures at either senior-management or board level within the postal group.
Dr Hower, who is also chief executive of Quantium Solutions - the global arm for SingPost's e-commerce logistics business - is leaving in August to pursue new career opportunities overseas, SingPost said.
The 38-year-old German national was a junior partner at McKinsey & Company in Dusseldorf before becoming SingPost chief operating officer on Jan 3, 2012.
Market watchers said Dr Hower's departure was not unexpected as he was seen as close to Dr Wolfgang Baier, who announced last December he was quitting as SingPost chief executive.
Dr Baier is an Austrian and a former partner at McKinsey.
Five directors will have left the board by the coming annual general meeting next month. Mr Keith Tay, Mr Goh Yeow Tin and Dr Baier have resigned. Mr Lim Ho Kee, who quit as chairman last month, and Mr Tan Yam Pin will not seek re-election when their terms end next month.
These departures follow a series of corporate governance missteps.
Drew & Napier and PricewaterhouseCoopers were appointed by SingPost to carry out a special audit after it emerged that Mr Tay was a shareholder and chairman of the financial adviser to three freight forwarders the postal service provider bought in 2013, 2014 and last year. The auditors found that Mr Tay was "arguably in breach... of the Companies Act" for not declaring his interest in SingPost's 2013 acquisition of freight forwarder Famous Holdings "as soon as practicable".
Last month, the Accounting and Corporate Regulatory Authority said it was probing possible Companies Act breaches by SingPost.
New SingPost chairman Simon Israel has moved quickly to fix the shortcomings as well as to restore investor confidence at the firm, which has seen its stock tumble 19 per cent in the past 12 months.
Last week, the company unveiled a code of business conduct and ethics for its directors, along with new policies governing directors' conflicts of interest, and board renewal and tenure.
Correction note: A previous version of the story stated that Dr Baier is German instead of Austrian. This has been corrected. We are sorry for the error.