CBI raided a dozen premises across NCR today in the alleged scam in Commonwealth Games overlays contracts including at an office under the Union Sports Ministry, as it registered a fourth FIR naming for the second time a top Games official V K Verma.

The searches that began early this morning were conducted a day after CBI questioned CWG Organising Committee(OC) chief Suresh Kalmadi for about nine hours.

Official sources said the office of the International Sports Division under the Ministry of Youth Affairs and Sports and premises of Nussli India and Comfort Net consortium and Pico Deepali were among those searched. Pico's Indian arm--Deepali Designs--is stated to be owned by a relative of senior BJP leader Sudhanshu Mittal.

The sources said the CBI raids were focussed on four companies, which had acted as the Indian arm for an identical number of international firms. The contracts were bagged by consortium of foreign and Indian firms.

The sources said a large number of documents including in digital format, have been seized from various premises in today's searches.

The overlays contacts are also under the scanner of the Income Tax Department and the Enforcement Directorate.

The FIR making Verma, a key aide of Kalmadi and the Organising Committee(OC) Director General, an accused again in a separate case was registered yesterday. The total value of the overlays contracts that are under scanner is over Rs 600 crore.

Verma's name also figured in the third FIR filed by CBI in connection with the Rs 107 crore Swiss Time Keeping deal along with that of CWG Secretary General Lalit Bhanot.

He had earlier been questioned by the CBI in connection with irregularities in Games projects.

Overlays works included supply of tents,marquees, prefabricated units, portable toilets, containers, security fences, furniture, public display LED boards, floor finishes, material handling equipment, gensets, cabling, UPS, air-conditioners, lighting, civil construction, athletic exercise equipment and grandstands.

The CBI had earlier registered three FIRs for alleged corruption in projects and events in the run up to the sporting extravaganza.

Two of these cases were in connection with alleged irregularities in the Queen's baton relay.