Officers of the CBI and NTPC's Vigilance Office on Thursday carried out a surprise check at the Barh Super Thermal Power Station in Bihar, the authorities said.
The check was initiated after allegations were made of violations in awarding tenders to firms at double the estimated cost, the Central Bureau of Investigation said in a statement.
"The role of NTPC officials, local contractors and influential people is also suspected," the CBI said.
During the the surprise check, teams of the CBI and NTPC officials collected relevant documents and further action will be taken after scrutinising them, the probe agency said.
--Indo-Asian news Service
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