Domain has reported that the property was sold late on Wednesday to an Australian buyer who had immigrated from China.
Martin Ross, of Black Diamondz Concierge, and Bill Malouf, of LJ Hooker Double Bay, confirmed to Domain that the residence sold in that price range on Wednesday night.
The property was listed in February by former tobacco executive Bill Webb with a guide of $40 - $45 million.
The sale also set a non-waterfront house record for Sydney, just bettering the $39 million paid for the Villa del Mare mansion a few doors away late last year by Chinese billionaire Xu Jiayin.
Mandalay was last traded in 2004 for $20 million by businessman Kerry Manolas who purchased it in 1978 for $440,000.
The hilltop property with views of the Harbour Bridge and Manly was originally built in 1954, before being redesigned in 1994.
