BEIJING - The Ministry of Railways on Sunday dismissed at least 10 railway officials and fined local railway authorities for contract fraud that led to unqualified subcontractors - including a former cook - using substandard material to build bridges in Northeast China.

The ministry also ordered the demolition of 16 piers of two extra-big bridges - part of a 2.3 billion yuan ($360 million) railway project - in Jingyu county and Fusong county in Jilin province. These will be reconstructed.

The dismissed officials were working for: owner of the 74.1-km-long rail project, Shenyang Railways Bureau, general contractor, China Railway No 9 Group Co, and the supervisor of Shenyang Railways Construction Supervision Company.

Publicity officials of the general contractor told Xinhua, "At least 10 officials were dismissed over the case, excluding those who would possibly be handed over to judicial authorities".

Also, China Railway No 9 Group and Shenyang Railways Construction Supervision Company were fined to cover the reconstruction costs and were disqualified from making bids for railway contracts for a year.

Calls to the Group and Shenyang Railways Bureau on Sunday afternoon went unanswered.

The ministry said that investigations were conducted, following up media reports of contract fraud, illegal subcontracting and compromising on quality published in October, and the allegations were found to be true.

Early media reports said China Railway No 9 Group subcontracted the project to several companies, including one from East China's Jiangxi province, which, in turn, engaged migrant workers to build two extra-big bridges and a tunnel.

But the Jiangxi-based company made an announcement in September, saying a group of frauds had forged the company's stamps, passing themselves off as company staff who carried out the project with China Railway No 9 Group.

The ministry concluded a deputy director of the railway construction project headquarters had "introduced" the migrant crew to carry out part of the tasks. But no official from the Shenyang Railways Bureau was found to have been involved in the contract fraud, the ministry said.

Lu Tianbo, who previously owned a restaurant and recently headed a team of laborers building the bridges, said the workers had substituted concrete with large quantities of gravel and rocks to build the piers.

Worker Chai Fangze told local newspapers, "Truckloads of waste were dumped into piers when stones were in short supply."

Project managers reportedly passed quality assessment forms without questioning.

This was not the first time that under-qualified laborers had built sub-standard bridges.

In August 2007, a 328-meter-long bridge under construction over the Tuojiang River in Hunan province collapsed, killing 64 people and injuring 22. The gravel inside was exposed when the piers broke.

The railway authority had spent heavily on infrastructure construction in China. Over 800 billion yuan was invested in 2010. The overall investment from 2011 to 2015 is expected to amount to 2.8 trillion yuan, according to official figures.

Dong Yan, a researcher with the National Development and Reform Commission, has warned that "a great many of the biddings for railway supplies and projects are trivial, and these bids, once acquired, tend to be exploited for corrupt practices."

In February, the Minister of Railways, Sheng Guangzu, urged Party and administration officials to not exert any influence on railway projects or procurements.