NEW DELHI: Over 300 personnel of Income Tax Department today swooped down on over 50 premises of companies across the country to probe alleged financial irregularities in Commonwealth Games contracts.Official sources said the simultaneous raids in various cities, which began early morning, are centred on four main contractors roped in by the CWG Organising Committee for landscaping and beautification works of the venues among others.The sources said over 50 premises spread across Delhi, Bangalore, Mumbai, Jamshedpur, Kolkata and National Capital Region (NCR) were the focus of the raiding teams and a large number of documents including those pertaining to contracts and sub-contracts awarded in connection with the Games have been seized.They said the contractors, who are under the scanner of the I-T Department, were involved in landscaping, beautification of venues, changing of street lamps, laying field tracks and also in the business of sports equipment and gear.The sources said the tax return details of previous years filed by these firms were also being examined by the department.The action comes at a time when various other government agencies including the Enforcement Directorate, CBI, Central Vigilance Commission and also the Prime Minister- appointed Special Committee are looking into various aspects of the alleged financial irregularities.The sources said the I-T probe will specifically look into the contracts awarded by the Games Organising Committee (OC) and the role of its officials and contractors besides charges of bribing.The I-T department officials have seized documents to detect possible evasion of taxes through over-invoicing and fudging of accounts.The department had on October 19 carried out similar searches on four major consortia, including those related to BJP member Sudhanshu Mittal, which had bagged contracts worth Rs 700 crore. Mittal is considered to be a close associate of former BJP President Rajnath Singh and late party leader Pramod Mahajan.