The Central Bureau of Investigation has launched a probe into the allegations of corruption and use of “sub-standard material” in executing a contract for the construction of a helibase at the high-security BSF campus in Srinagar.Four Central Public Works Department engineers — Umesh Chandra, Sanjay Kumar Srivastava, Prabhat Singh and Sharvan Kumar — have been booked along with the government contractor, Ghulam Mohi-u-din Bhat & Sons.The contract also pertained to the construction of chain-link fencing adjoining the airbase with a provision of helicopter hangar at the BSF campus. The contract worth ₹2.11 crore was awarded to Mr. Bhat, of Budgam in J&K.It is alleged that the engineers conspired with the contractor to cheat the CPWD by submitting fake invoices of cement and TMT steel and also used “sub-standard material” in the execution of work that had started in March 2014 and completed in September 2015. The accused contractor had submitted fake retail invoices for about 42.76 metric tons of steel worth ₹24.35 lakh and about 23,880 cement bags for ₹1.06 crore.The probe “also revealed that extra cement for ₹28 lakh approx. has been provided by the above mentioned CPWD officials in the 6th and final bill, in addition to the basic quantity of cement to the contractor agency, thus providing undue benefit to the said contractor and subsequent loss to the government exchequer has been caused”. The accused persons had also showed deployment of technical staff at the work site, as required under the contract conditions. Investigations revealed that no such officials were deployed and that the payments for the same were shown on paper.