A mainland contractor that supplied concrete for one of Hong Kong’s biggest infrastructure projects hit by a safety scandal was involved two years ago in a court case over its purchase of substandard rockfill for the multibillion-dollar venture, it has emerged. The government .on Friday confirmed the role of China Harbour Engineering Company in the construction of the Hong Kong-Zhuhai-Macau Bridge following the arrest of 21 employees of contractor Jacobs China by graft-busters last week. They are accused of faking concrete test results for the project by altering time stamps and switching samples. Officials admit problems with Hong Kong-Zhuhai-Macau bridge were missed a year ago The government said China Harbour was the supplier of a ship manufacturing concrete for part of the bridge project. The mainland firm was also reportedly involved in the production of concrete with its partner. The firm is a subsidiary of state-owned giant China Communications Construction Company, which is the lead contractor for the design and construction of artificial islands and tunnel work for the main bridge project on the mainland side. China Harbour is also part of the Dragages-China Harbour-VSL Joint Venture, the contractor building the 9.4km dual three-lane viaduct section of the Hong Kong Link Road at a cost of HK$12.8 billion. The firm has not been linked to the latest scandal to hit the bridge. The government so far is unable to identify which parts of the bridge may have been compromised by the alleged faking of concrete test results. In an unusual move, the Independent Commission Against Corruption has made it a point to clarify there is no evidence of wrongdoing by government officials or other contractors . China Harbour was involved in a court case in April 2015 in which a senior foreman was jailed for 15 months for trying to bribe a consultant into accepting substandard rockfill purchased for the bridge construction project. The court heard that in 2013 the foreman offered HK$50,000 to an employee of Ove Arup, an engineering firm assigned to inspect the quality of rockfill purchased by China Harbour. The rockfill, for filling up structures supporting artificial islands at the bridge site, did not meet standards, the court was told. The firm did not respond to inquiries on Friday night. Speaking for the first time on the scandal on Friday, Chief Executive Leung Chun-ying also cited the ICAC statement, saying there was no evidence so far to suggest that any public officers, other contractors or material suppliers were involved in the corruption. Lo Wai-kwok, chairman of the Hong Kong Quality Assurance Agency, said he was “angry” at those involved in the fake testing and warned that it may have hurt the reputations of those in the engineering and construction business as well as the testing and certification industries.