The case concerns alleged corruption in relation to the submission of false concrete compression test reports. The arrests were of two senior executives and 19 staff members of a contractor used by the Civil Engineering & Development Department (CEDD). The 19 staff members are two senior site laboratory technicians, 12 site laboratory technicians and five laboratory assistants.

The investigation arose from a corruption complaint referred by the CEDD. Since January 2013, the CEDD had engaged the contractor to conduct compression tests on samples of concrete to be used for the bridge project. The test for each sample was required to be conducted within a set time and all concrete samples (in cube form) were required to pass the test.

It was revealed that when some of the tests were not conducted within the set time frame in compliance with the contract requirements, the site laboratory technicians and laboratory assistants might have adjusted the times on the testing machines to cover up the irregularities.

During the ICAC operation, it was further revealed that some of the laboratory staff might have replaced the concrete samples by using a metal calibration cylinder and/or high strength concrete cubes to falsify the tests, so that the tests would appear to have been conducted properly. It was suspected that the above malpractice might have started in early 2015.

ICAC enquiries revealed that the two senior site laboratory technicians had certified the false test reports. It was suspected that they might have corruptly connived at the submission of the false reports to the CEDD.

A statement from ICAC said that, when irregularities were initially detected in the concrete compression test reports by the CEDD, the contractor conducted an internal investigation into the matter. However, the use of the metal calibration cylinder and/or high strength concrete cubes to falsify tests was not disclosed in the investigation report that was submitted to the CEDD. It was suspected that the contractor might have submitted the misleading investigation report to the CEDD to defraud the department.

All the arrestees have been released on ICAC bail. Enquiries are continuing.