Three Taipei City Government officials were taken into custody on Thursday for allegedly allowing inferior materials to be used in the construction of asphalt roads in return for bribes from construction companies.

Prosecutors suspect that the officials in question took several million New Taiwan dollars in bribes over a period of more than six years, on dozens of road projects in Taipeis Neihu and Wunshan Districts.

According to prosecutors, the officials are suspected of accepting bribes to help companies win bids for road backfill projects after the Taiwan Power Company and other government agencies dug up roads in the nations capital to install underground electricity cables.

The thickness of asphalt layers laid by some companies was only 3 to 3.5 centimeters, much thinner than the 5-centimeter minimum thickness required by law, but officials allegedly turned a blind eye to the irregularities.

Taipei prosecutors Wednesday led nearly 40 investigators in raids on 10 locations, including the city government building and homes of people involved, and questioned a total of five officials and six construction firm operators as part of the investigation.

Among the 11 questioned, prosecutors obtained the Taipei District Courts permission to detain three officials and the alleged briber Wang Chi-ming, while the other seven suspects were released on bail ranging from NT$50,000 to NT$300,000.

The three officials detained - Chien Tien-chang, Chang Chun-ting and Chen Ming-kuan - were technicians working under the city governments New Construction Office.

The two officials released on bail included city government official Wu Chin-tang and a technician at the Wunshan District Administration, Lin Chun-hao, who is believed to have acted as a middleman in the bribery case.

Lin shouted at the press, "Go ahead and take pictures of me!" as he left the Taipei District Prosecutors Office surrounded by reporters and photographers.

The prosecutors were reported to have said they are not excluding the possibility that other higher-ranking officials may have been involved.

Following the courts decision to approve detention of the three officials on grounds of the severity of the allegations, Taipei Mayor Hau Lung-bin （郝龍斌） announced that the three detained officials had been dismissed, while Wu and Lin were to be transferred to lower posts.

Hau disclosed that former Taipei Mayor Ma Ying-jeou （馬英九）, the opposition Kuomintangs 2008 presidential nominee, was paying close attention to the case and that Ma had told him to take corruption cases seriously when he took over as Taipei mayor at the beginning of this year.

In 2006 former Taipei City Councilor Hsu Fu-nan and 24 former city government employees were indicted on corruption charges for taking bribes from road construction companies. Prosecutors have recommended lifetime imprisonment for Hsu in the ongoing case.