Former Westfield co-chief executive Steven Lowy warned in May that OneMarket, the retail technology start-up spun out of the shopping centre giant after a $30 billion takeover by Unibail-Rodamco, was high risk.

"It is a technology company, not a real estate company, and therefore carries a higher risk profile associated with such ventures," Mr Lowy, the chairman of OneMarket, told investors ahead of the demerger.