New Delhi: Delhi govt has launched an investigation into residential, commercial and group housing projects where building plans were allegedly approved in the past five years without the payment of the mandatory infrastructure development charge (IFC).Govt estimates this has caused a revenue loss running into thousands of crores of rupees.According to Delhi Jal Board (DJB) minister Parvesh Verma, who has ordered the scrutiny amid allegations of irregularities, it has been found out prima facie that several applicants obtained building plan and layout approvals from Municipal Corporation of Delhi (MCD) using official DJB letterheads instead of valid no-objection certificates (NOCs) confirming payment of the infrastructure charges.He suspects the role of DJB engineers, on the verge of retirement, and MCD staff behind this evasion.The govt move could result in notices being issued to property owners who carried out construction over the past five years without depositing the mandatory IFC. Dues will be recovered from them. Verma said govt suspects that in many cases, people did not pay anything at all to DJB, yet got the approval.DJB levies IFC on new construction and property redevelopment to fund water and sewer networks in the city.Verma said govt has sought data from officials on the number of building plans approved by MCD over the past 10 years, five years and one year, and how many of these applicants deposited the mandatory charge.A preliminary scrutiny covered around 300 properties measuring more than 3,000 square metres. “It found owners of nearly 70% of these properties got their building plans approved without depositing IFC,” he said, adding that verification of other properties constructed during the past five years was also underway.Verma said once the exercise is completed, govt will recover IFC from property owners who have not deposited it. He said their properties could be sealed if they don’t pay up.He added that despite govt reducing IFC by up to 70% this May, irregularities in its collection were still being reported.For Category A and B colonies, the charge was slashed from Rs 13.2 lakh to Rs 5.4 lakh. In Category E and F colonies, it was reduced from Rs 3.3 lakh to Rs 2.7 lakh. For Category G and H colonies, govt brought down the charge from Rs 3.3 lakh to Rs 1.6 lakh. It has maintained that this was intended to ease the financial burden on property owners.