MUMBAI (AFP) - The US government has sold a former maharaja's mansion in Mumbai to an Indian billionaire for US$105 million (S$148 million), the businessman's son said on Monday (Sept 14), four years after it was put on the market.

Lincoln House was home to the US consulate from 1957 to 2011 after it was purchased from a local maharaja (prince) who sold it to pay off his taxes.

Cyrus Poonawalla, one of India's richest men and founder of vaccine manufacturer the Serum Institute, has purchased the seaside mansion in the south of the Indian commercial capital for seven billion rupees.

"We decided to go ahead with the deal given the market conditions and the good price to go with it," Cyrus's son Adar Poonawalla told AFP via email.

"In south Mumbai this is an ideally located, pristine and iconic Heritage property even though this will mean that no redesigning will be permitted," he added.

Adar Poonwalla, who is CEO of Serum, said the total cost including taxes could reach eight billion rupees (S$17 million).

"The possession would be effected in approximately two months time and shall be utilized for the residence of the Poonawalla family," he said.

The protected building, built in the Breach Candy area of the city in 1938, occupies two acres of land and looks out on the Arabian Sea. It was previously known as Wankaner Palace after the maharaja who owned it.

The US consulate moved to a purpose-built facility in Mumbai's north in 2011. A spokesman at the consulate refused to comment on the sale of Lincoln House.