May 28 (Bloomberg) -- Japanese Agriculture Minister Toshikatsu Matsuoka, under fire for accepting questionable political donations, died today at a Tokyo hospital. He hanged himself, Japanese media reported.

Matsuoka, 62, was pronounced dead around 2 p.m., Chief Cabinet Secretary Yasuhisa Shiozaki said at a press conference in Tokyo, declining to comment on reports by Kyodo News and other agencies that he committed suicide.

``As the person who appointed him, I feel responsibility for his action,'' Prime Minister Shinzo Abe said. ``This will have a great impact on the cabinet and the administration.''

Matsuoka's death came on the same day two newspapers showed Abe's approval ratings plunging ahead of July's parliamentary upper house elections. Abe, who took office in September, is trying to keep his ruling Liberal Democratic Party-led majority.

``This is a personal blow for Abe,'' said Koichi Nakano, a political science professor at Sophia University in Tokyo. ``He has a very hard election to win anyway. This isn't an easy thing to deal with and may cause a sense of panic among the LDP.''

If Matsuoka's death is ruled a suicide, it would be the first by a Cabinet member since World War II, Deputy Cabinet Secretary Hiroshi Suzuki said.

``It is a great pity,'' Abe told reporters. ``I will pray for his soul to rest in peace.''

Matsuoka was criticized in January after a support group of his claimed expenses for a rent-free office. Two separate campaign offices also allegedly received 13 million yen ($107,000) in donations from contractors for rigging construction bids, Kyodo News said today. He was scheduled to appear before a parliamentary committee today for questioning.

Left Note

The Nikkei 225 Stock Average briefly pared gains this afternoon after Kyodo News reported Matsuoka's death, before recovering to close 0.6 percent higher at 17,587.

The minister was found by an aide at his residence, according to Kyodo, which said he hanged himself and left behind a note. Abe, speaking after paying his respects to Matsuoka's family at the hospital, said he had no idea of the contents of the note.

Abe's approval rating fell 11 percentage points from April to 32 percent, the lowest since he took office, the Mainichi newspaper said today. His disapproval rating rose to 44 percent, from 33 percent. Today's Nikkei newspaper survey put his rating at 41 percent, down 12 percentage points from a month ago. Neither newspaper provided a margin of error.

Both papers attributed the drop in popularity to anger over a government agency's failure to keep accurate records for Japan's 30 million pensioners. The ruling coalition, led by Abe's Liberal Democratic Party, introduced a bill on May 25 to improve the Social Insurance Agency, which has 50 million unidentified payment records.

Professional Agriculturalist

Matsuoka joined the agriculture ministry in 1969 as a bureaucrat after graduating with a degree in agriculture from Tottori University. He was first elected to the lower house of parliament in 1990 and was re-elected five times, specializing in farm-related topics.

``Mr. Matsuoka was an agriculture expert, and the Prime Minister appointed him with great expectations,'' Shiozaki said.

Abe named Matsuoka to his Cabinet upon taking office in September. Environment Minister Masatoshi Wakabayashi was named as a temporary replacement, Shiozaki said.

A special election to replace Matsuoka's seat in the lower house of parliament will take place on the same day as the July 22 upper house elections, Asahi newspaper said, without saying where it obtained the information.

To contact the reporter on this story: John Brinsley in Tokyo at jbrinsley@bloomberg.net; Sachiko Sakamaki in Tokyo at ssakamaki@bloomberg.net

Last Updated: May 28, 2007 07:08 EDT