As raids continue in the city over the transferable development rights (TDR) scam, Anti-Corruption Bureau (ACB) officials investigating the case believe that the revelations made during the initial probe are only the tip of the iceberg. While there are suspicions that the scam — if investigated thoroughly — could run into several thousand crores, sources in the ACB told DH that the current probe hints at irregularities running to the tune of at least Rs 600-700 crore.

The scam pertains to the illegal sanctioning of TDR to parties not eligible for it through various fraudulent means. ACB officials have currently exposed four different modes in which the scam was run by a few BBMP officials in cahoots with real estate agents and firms.

While the agency has filed FIRs in connection with illegal sanctioning of two development right certificates, it has detected irregularities in “another 20-25 DRCs”, which are being probed, according to M Chandra Sekhar, additional director general of police, ACB.

Though there were allegations of irregularities in TDR in the past, the scam came out in the open after a complaint by one Syed Aslam Parveez in February. The complaint was transferred to the ACB on April 11, which filed an FIR with Krishna Lal, assistant executive engineer of BBMP — who was deputed to BDA — as accused number 1.

In the case, the engineer, along with another accused B S Surendranath, sanctioned two development right certificates and sold them for Rs 56.37 crore, resulting in losses to the BBMP. Following the case, searches were carried out on the residence of Lal and his two associates on April 26. Subsequently, sleuths raided two private surveyors and four persons of a real estate firm.

“Indications are that many more people are involved in this multi-crore scam,” Chandra Sekhar said.