The resignation of Hong Kong's Financial Secretary Antony Leung comes after months of criticism over his purchase of a luxury car.
Antony Leung donated money to charity after the car scandal
Mr Leung bought a $100,000 (HK $790,000) Lexus, just weeks before he announced a tax hike on such vehicles in March.
He denied he was trying to avoid the new tax, which would have cost him several thousand dollars.
Hong Kong's Chief Executive Tung Chee-hwa censured him for "serious negligence", but said he believed the minister had made an unintentional mistake.
The Justice Department said on 16 July that it was still considering whether to bring corruption charges against Mr Leung.
Mr Leung has said he decided on the tax increase after buying the Lexus, which he said his family needed because of the arrival of his first-born, a daughter.
Mr Leung married Fu Mingxia in July 2002
Reports said he already owned a Porsche and a four-wheel drive Toyota Land Cruiser.
Mr Leung, who was born in 1952, was a little-known international banker before taking over as financial secretary in May 2001.
Last year, in Hawaii, he married Chinese Olympic gold medal diver Fu Mingxia, four years after he was divorced from his first wife.
Four-times gold winner, 24-year-old Ms Fu came to worldwide attention 12 days before her 12th birthday when she won gold at the 1990 Goodwill Games.