Yu was intercepted by law-enforcement personnel at Kaohsiung International Airport while he was attempting to leave the country early yesterday.

He has come under investigation after being listed as a potential suspect in the case of alleged bribery in connection with the construction of an exhibition hall in Taipei's Nangang District in 2003.

Lin Chin-tsun, deputy chief prosecutor of the office, said the prosecutor in charge of the case filed for a court order to detain Yu after investigators found that Yu was possibly involved in leaking confidential government information, profiteering, and colluding with suspects in the case.

Lin said Yu was barred from leaving the country before the prosecutors office summoned him on Oct. 7 to report to the office today as a potential suspect.

According to the prosecutors office, Yu is suspected of leaking the names of members of a committee that was responsible for screening the bids for the costly construction of the Nangang Exhibition Hall in Taipei, a brand new annex to the Taipei World Trade Center at the Xinyi Commercial District.

Yu made the name list available to the company that eventually won the bid during his tenure as minister of the interior in the period 2002-2004, the prosecutor charged.

The DPP, which became the opposition party in May after holding power for eight years, blasted the law enforcement agencies for violating Yu's rights.

Yu was already on the Macau-bound plane when immigration officials and airport police came on board and demanded he get off, according to Legislator Chiu Yi-ying from the DPP.

Chiu protested that prosecutors were making an unnecessary move of blocking the former minister's overseas trip in violation of his rights.

According to Chiu, Yu had received a summons late Tuesday night requiring him to attend an interview this morning in the capacity of a witness to the case.

Yu, who had already made plans for the Macau trip well in advance, had his lawyer ask for a leave of absence for Thursday's session.

"We can't believe that the district prosecutors could ask Yu to get off the plane. This is a total disregard of his rights," said Chiu.

She said it was unreasonable for the prosecutors to make Yu a suspect so suddenly. It was also outrageous that some TV news even claimed that Yu was trying to flee the country, Chiu said.

"It is impossible that Yu would want to flee," Chiu maintained.

The exhibition hall project was contracted to Rich Development during Yu's stint as interior minister. Prosecutors are investigating allegations that bribery was involved in awarding the contract.

Last month Yu, as a witness, told prosecutors during an interview that the exhibition hall was handled by the ministry's Construction and Planning Administration, and he was unaware of any corruption stemming from the project.

Prosecutors believe that Yu is suspected of illegally helping Rich Development win several government projects.

Name list

Prosecutors decided to take action after Kuo Chuan-ching, chairman of Rich Development, gave all the details concerning bribing, including whom he had bribed and where the money went.

Kuo also confessed that he had given NT$90 million to Tsai Ming-jer who transferred the money to the family of former President Chen Shui-bian, according to sources handling investigation.

Kuo was able to get the name list of a panel for evaluating and awarding the contract of the Nangang project well in advance for a competitive edge over other bidding firms.

Kuo, who had been detained since September for the probe, was set free yesterday because prosecutors decided that he had revealed all the necessary information.

Tsai is a brother of Tsai Mei-li, who has been an intimate friend of former first lady Wu Shu-chen when they studied together at university.

A separate team of prosecutors investigating the embezzlement of public funds by former President Chen's family and their money-laundering operations through other people's bank accounts abroad.

The Tsais are among those who agreed to let the former first family to use their overseas bank accounts to deposit their money.

Powerful family

Coming from a politically powerful family, Yu has long been a major pillar of the DPP in southern Taiwan.

His grandfather, mother and an uncle, plus himself, had been elected magistrate of Kaohsiung County.

Yu, aged 49, also served as legislator while his younger brother Yu Cheng-dao, a sister, and an aunt were also elected as lawmakers.

He was promoted as interior minister by Chen in 2002 and resigned two years later after Chen and then Vice President Annette Lu were both shot by mysterious gunmen at Chen's power base in southern Tainan in March 2004.

Yu was then appointed as chairman of the state-owned Taiwan Sugar Corp.

He was defeated by Kuomintang candidate Lin Yi-shih in the legislative election held in January this year when he attempted to return to the Legislative Yuan.

But his younger brother Yu Cheng-dao was still given a seat as a lawmaker-at-large representing the DPP in the parliament.