Prosecutors demanded a 10-year prison sentence Thursday for fired Foreign Ministry official Katsutoshi Matsuo, who stands accused of embezzling 500 million yen from the Cabinet Secretariat's discretionary funds from 1997 to 1999.

"The incident involving such a large amount of money is unprecedented in the history of crimes committed by public servants. (Matsuo) seriously undermined the public's faith in the Foreign Ministry and its officials," the prosecutors said in a statement before the Tokyo District Court.

Judge Hiromichi Inoue said the court plans to hand down a ruling on March 12 after defense lawyers make their final argument on Dec. 27.

Matsuo "spent taxpayers' precious money like water to fulfill his selfish desires, such as dating women other than his wife and owning racehorses," the prosecution said.

"He pocketed more than 80 percent of the money he embezzled and can return only around half of it even if he sells his assets," it said.

Matsuo, 56, admitted during previous hearings that he swindled the government and misappropriated public money, saying, "I offer my sincere apology to the public for causing them a lot of trouble."

He also said, "I will spend the rest of my life paying back the defrauded money."

Matsuo stands accused of swindling the government out of some 500 million yen in discretionary funds by padding hotel bills in connection with 14 overseas trips by prime ministers from 1997 to 1999.

He was chief of the ministry's now-defunct Overseas Visit Support Division from October 1993 to August 1999, arranging overseas trips for prime ministers and other top officials. The ministry fired Matsuo on Jan. 25.

The scandal rocked the ministry, resulting in the arrests of several other officials on suspicion of embezzlement. Another ex-ministry official, Akio Asakawa, was charged in late September with defrauding the state by padding hotel bills for international meetings.

Ministry personnel also allegedly amassed funds for parties and personal use by such means as having hotels pad bills to the ministry.

Two ministry officials are to be fired over that affair.