The buyer of the most expensive home ever sold just north of the Harbour Bridge in Sydney has emerged as little-known north shore resident, 33-year-old Manrong Xu.

While the identity of the deep-pocketed buyer left several agents and buyer’s agents scratching their heads, a search of company records revealed Xu, who was born in the Jiangsu province in eastern China, is a director of West Australian-based company QZ Fortune Investment and resides at an address in East Killara.