The U.S. government has secretly sold one of its largest properties in Hong Kong to a mysterious buyer.

The U.S. Consulate General in Hong Kong confirmed Wednesday it had sold one of its luxury properties. The 90,000 square meter property included six multistory mansions at 37 Shouson Hill Road. The consulate didn't reveal the identity of the buyer nor did it reveal the price of the winning bid.

Bidding for the property was reportedly launched earlier in the year and closed in July. The sale is expected to be finalized before the end of this year. Property analysts have estimated that the value of the parcel of land located at one of the city's high-end areas was likely between HK$3.2 billion ($412.9 million) and HK$3.5 billion.

Real estate company Savills Valuation & Professional Services valued the property at around HK$3.2 billion. The company based its valuation on the sale of a similarly-sized property located at 39 Shouson Hill Road in 2018. Despite its prime location, the company estimates the final selling price may have been lower given the "politically sensitive" nature of the property. It also said the property market was substantially different in 2018 compared with this year.

Several real estate developers, including CK Asset Holdings, joined the bidding. CK Assets, the city's second-largest property developer, confirmed it was not the winner. Sun Hung Kai Properties, the city's largest developer, also confirmed it was not the winner. Other developers bidding - which closed July 31 - have yet to comment. Some said they were unable to disclose any further information as a result of the delicate political situation.

The luxury mansions built on the property all overlook Hong Kong's Deep Water Bay. One of the mansions was for a time the home of the city's financial secretary before it was sold. The U.S. consulate put the property on sale just three days before the China government imposed the national security law in the city to restore order after months of civil unrest.