Day after the CBI found former Noida chief engineer residence locked, the probe agency on Wednesday moved into the premises to conduct searches. According to CBI officials, Singh's residence in Sector 51 of Noida was purchased by the engineer in 2004 and has been a 'hub' of activities. The current spate of raids by the agency comes after Allahabad high court last month ordered that the CBI probe corruption charges against Singh following a PIL by RTI activist Nutan Thakur in which she accused Yadav of large-scale corruption during his brisk rise in the Noida Authority between 2007 and 2014, spanning the BSP and SP regimes.