Japan's agriculture minister died Monday after hanging himself hours before he was to face questioning in parliament over a political scandal, officials said.
Toshikatsu Matsuoka was found in his apartment unconscious and later died in a hospital, a police official said.
The general secretary of the Japanese Cabinet of Ministers, Yasuhisa Shiozaki, confirmed Matsuoka's death.
Matsuoka became a member of the lower house of parliament in 1990. Last year he was appointed minister of agriculture, forestry and fisheries.
News reports said the 62-year-old hanged himself while in his pyjamas using a dog leash attached to his living room door.
His death is a blow to Prime Minister Shinzo Abe and his government, whose approval ratings have plummeted amid the allegations. He had strongly defended Matsuoka, a political insider who had helped him rise up the ruling party.
Abe declined to elaborate on the political impact of the suicide, although he acknowledged Matsuoka "was under fierce questioning in parliament."
Matsuoka had become embroiled in a scandal involving political funding and bid-rigging.
Two committees set up to support his electoral campaigns allegedly received money from a group of businesses which then made bids for public works projects doled out by the government, according to media reports.
Prosecutors last week arrested two senior officials of the government body involved in the scandal, which involved contracts for building forest roads in Matsuoka's home district.
"I painfully feel the responsibility as a supervisory minister," Matsuoka had told reporters Friday of the arrests. "I believe it is my responsibility not to let anything like this occur again."
More than 30,000 people kill themselves every year in Japan, making the nation's suicide rate among the highest in the world.
Matsuoka, a career agriculture ministry bureaucrat turned politician, has also come under fire for allegedly claiming bills of up to 29 million yen (240,000 dollars) over five years to pay for utilities at his rent-free office.