Former Japanese finance minister Shoichi Nakagawa, who resigned his key post after being forced to deny he was drunk at a G7 news conference in February, has died, Tokyo police said today.

Authorities were trying to determine the cause of the 56-year-old, ex-lawmaker's death, who was found dead in a bedroom in his house in Tokyo, a police spokesman said.

The possibility of suicide is low, Kyodo News Agency reported, citing the police, adding he had been taking sleeping pills. No external injuries were found on his body and a will has not been found, a police spokesman said.

"I want to express my heartfelt condolences," current Finance Minister Hirohisa Fujii told reporters in Istanbul, where he was at a Group of Seven meeting. "He was doing a fine job as a finance minister, so it is regrettable."

The furore surrounding Nakagawa's resignation was a major embarrassment to ex-Prime Minister Taro Aso, whose Liberal Democratic Party was ousted in an August 30 election in which Nakagawa also lost his seat in parliament's lower house.

A graduate of prestigious University of Tokyo, Nakagawa was an outspoken conservative who entered politics after his father, an LDP heavyweight, who committed suicide in 1983 at the age of 57.