NEW DELHI: CBI on Thursday registered five cases of cheating and forgery in the supply of sewerage equipment to Delhi Jal Board . It also named eight executive engineers, six junior engineers and a private company. The agency was probing irregularities in DJB contracts given to private companies during the tenure of the previous government.After registering the FIRs, CBI teams raided 21 places in Delhi, Noida and Ghaziabad and seized incriminating documents. "Spurious and cheap items were sold to sewage treatment plants at exorbitant rates by showing the firm as authorized dealer of a manufacturing firm through forged papers," said CBI spokesperson Kanchan Prasad.It is alleged that DJB had cleared a Mumbai-based company, Esenpro, for supply of equipment. The DJB executive engineers allegedly conspired with Raman Gupta , the owner of Kirti Nagar-based Metro Projects and Sales Services, in 2009-12 to forge letters of the regional manager of Espenro . The forged letters declared his company to be an authorized supplier of Esenpro equipment in Delhi, sources said.Based on these letters, Gupta allegedly supplied equipment carrying forged Esenpro trademark worth Rs 6 crore to five DJB sub-divisions-Kondli, Keshopur Coronation Park, Maharani Bagh and Wazirabad. CBI has seized over 100 such letters with varying signatures during its searches."The accused officials issued work orders to the firm. Certain letters were also issued to the regional office of Esenpro in Delhi for technical support when the actual office was in Mumbai. The proprietor, Gupta, wrote to the engineers claiming himself to be the sole authorized dealer for spares, renovation and servicing of Essenpro make gear boxes," said a CBI officer.The executive engineers named in the FIR are Banwari Lal Bharti, Islam Khan, J P Garg, S C Vasishtha, Seeshram Singh, G P Singh, R K Bhalla and J K Arora. DJB chairperson and Delhi CM Arvind Kejriwal has said action will be taken against the guilty.