THIRUVANANTHAPURAM: In a setback to Chief Minister Oommen Chandy , a vigilance court today ordered further investigation in a case pertaining to alleged corruption in implementation of an effluent treatment plant at a public sector company here during his initial stint as Chief Minister in 2006.While considering a private petition, Vigilance Judge John K Illikkadan rejected the report submitted by Vigilance and Anti-Corruption Bureau ( VACB ), which had given a clean chit to Chandy holding that there was no ground in the allegation that placing the order with a private company for executing the plant involved corruption.The petitioner, an employee of the company, wanted further investigation in the case with Chandy, Home Minister Ramesh Chennithala, then KPCC President, and 10 others being arraigned as accused.While turning down the VACB report submitted in March 2013, the court asked the agency to conduct further investigation and file a fresh report within four months.The case pertains to alleged irregularities in implementation of an effluent treatment plant at Travancore Titanium Products Ltd ( TTP ), one of Kerala's oldest public sector companies located on a beach near the state capital.The issue had created a flutter in 2006 with the then Health Minister K K Ramachandran resigning. Ramachandran, a Congress leader, later alleged that he had been made a scapegoat by Chandy and others.