Two former Foreign Ministry officials and two former executives of a Tokyo-based limousine company pleaded guilty to fraud at the Tokyo District Court on Tuesday in the first hearing of a trial related to last year's Group of Eight summit in Okinawa.

Entering the guilty pleas were Hiromu Kobayashi, 46, former assistant director in the office of the deputy director general for general affairs at the Economic Affairs Bureau, his subordinate, Tsutomu Okuma, 38, Seiji Kobayashi, 60, former managing director of Hinomaru Limousine Co., and Yuji Takizawa, 52, head of the company's Akasaka office.

Kobayashi, who was stripped of his post along with Okuma shortly after his arrest, said, "It's correct," when told of the indictment charges.

"It's inexcusable as a national public servant to swindle public money," Kobayashi said. "I deeply apologize."

The four were indicted in August on charges of swindling the government out of about 21 million yen in public funds from March to September last year by padding bills for limousine rentals associated with the G8 summit.

More than 11 million yen of the total amount, mainly in the form of taxi vouchers, was channeled to Kobayashi and Okuma and more than 1.5 million yen was used by officials of the limousine company, according to the indictment.

Kobayashi and Okuma had worked under former Foreign Ministry logistics chief Katsutoshi Matsuo, 56, who was sacked in January over another fraud case related to logistics work at the ministry.

Matsuo is the key suspect in a series misappropriations of public funds that have shaken the ministry since January.

He has pleaded guilty to swindling the government out of some 500 million yen in secret government funds while in charge of coordinating overseas trips for prime ministers.

Another case resulted in fraud charges against Akio Asakawa, 56, assistant director at the ministry's European Affairs Bureau.