Railway authorities are investigating a 2.3-billion-yuan (US$360 million) railway project in northeast China, after it emerged that subcontractors included a non-existent company and small, unlicensed players who skimped on materials.

Construction on the line linking Jingyu County with Songjianghe County in Jilin Province has been suspended pending a further probe by the Shenyang Railway Bureau and China Railway No. 9 Group, the main contractor on the project, Xinhua news agency reported yesterday.

"If quality issues are discovered in railway bridge piers, we will knock them down and build new ones. All costs will be borne by Railway No. 9 Group," a director, surnamed Qiu, in charge of publicity, told Xinhua.

Railway No. 9 Group subcontracted work to a large number of smaller firms, including companies with no experience of bridge construction, Xinhua said.

Fraudsters also picked up contracts. Some work was awarded to "Jiangxi Changxia Construction Engineering Group," but this turned out to be a fake company created by conmen who forged seals and documents, the report said.

A real Jiangxi Changxia does exist, but has no dealings with Railway No. 9 Group.

The people who signed contracts are fraudsters, said the company's lawyer, surnamed Huang.

The bogus company then subcontracted projects to unqualified workers.

Lu Tianbo, a migrant worker who had previously been a cook, and other builders in charge of constructing bridges and tunnels had no knowledge of construction and their credentials were never checked, the report said.

Safety concerns were raised after Lu and other workers admitted they cut corners on materials. Bridge piers supposed to be reinforced with cement were instead filled with rubble, Lu told Xinhua.

They are likely to warp or even collapse in the future, a researcher with the Bridge Science Research Institute told Xinhua.

Railway No. 9 Group admitted bidding process errors. But an official, surnamed Wang, said the fake company was introduced by a high-ranking official, Xinhua reported.