The Central Vigilance Commission has asked the Oil and Natural Gas Corporation for an explanation as to why the company was planning to hire drilling rigs without following the standard procedure of issuing tenders, The Economic Times reported on Thursday.

In 2015, ONGC was planning to hire nine rigs through nomination in order to save time. The company changed its plans, however, after media reports picked up on this. Oil rigs, used to drill wells and extract oil and natural gas, can cost more than a few lakh dollars a day on rent.

“The CVC has taken a harsh view of the matter,” said an unnamed official. “ONGC’s initial explanation has cut no ice with the CVC. The company said it was just a plan that remained unexecuted. But CVC wants to know why ONGC drew such a plan in the first place.”

Public sector oil companies are supposed to follow the nomination process while hiring only under exceptional circumstances.