The CBI has arrested a Kochi-based chief engineer of the Military Engineering Services and five others and recovered an alleged bribe of Rs 1.21 crore, officials said here today. Searches were conducted in 20 locations, including the home of Rakesh Kumar Garg, who is posted as chief engineer (naval works) MES in Kochi, they said. The raids, which began yesterday, covered several cities, including Delhi, Kochi, Ajmer and Kolkata. During the searches, an additional recovery of Rs 3.97 crore and six kilograms of gold biscuits was made by the agency, the sources said. The searches were made after the agency received inputs that Garg was "collecting and demanding illegal gratification of 1 per cent of contract amount from the contractors for issuing various civil contracts in the Kochi naval base", officials said.