Gannon Dunkerley and Company Ltd (GDCL) had bagged the award for construction of the 275-metre chimney for the power plant.

At the crash site, dozens of workers and women were seen beating their chests and wailing, fearing the worst for their trapped kin and colleagues.

Meanwhile, the opposition Congress sought a Central Bureau of Investigation (CBI) probe into the accident, asserting that the agency needed to 'unravel several mysteries behind the tragedy', including the role of the Balco management.

'Even after three days, the Balco management is not in a position to tell the exact number of workers who were under the ruins of the chimney, and hardly 10 percent of the debris has been cleared till Friday evening,' Dhanendra Sahu, state Congress president, told reporters here.