Rich Lister Emma Gibson has resigned as chief executive of wellness start-up Aquamamma, leaving behind millions of dollars of unpaid invoices owed by the company, with about 20 employees quitting in the past 18 months and an investigation into non-payment of superannuation and tax under way.

Contractors ranging from social media influencers to shipping companies have sent Aquamamma legal notices and letters demanding payment. One German shipping company is refusing to release $1 million worth of product from the Port of Melbourne, where it is gathering demurrage and detention fees.