Opposition was vociferous while raising the issue in the Rajya Sabha, seeking to corner the government by demanding a statement from prime minister or coal minister on the issue.
Responding to the demand, Minister of State for Parliamentary Affairs Rajeev Shukla assured the House that Coal Minister Sriprakash Jaiswal will make a statement on the issue but gave no time frame.
Raising the issue during Zero Hour, BJP's Dharmendra Pradhan said such an incident has never happened earlier and the government needs to reply.
"This is a very serious issue... Nothing can be more condemnable. This is a conspiracy... It is an attempt to save the prime minister," said Pradhan, wondering if the coal department had a hand in missing of files to protect the prime minister from any allegation as he held the Coal portfolio earlier.
Noting that the coal block allocation is being probed by CBI, Leader of Opposition Arun Jaitley said, "There are three powerful targets of investigation and suddenly the files are missing...the government must respond to this...Otherwise you eliminate the evidence and then say no crime is committed.
"There are three important targets of investigation -- the beneficiaries who benefited from coal block allocations, the screening committee which allotted the mines and the minister, the minister's office and the Prime Minister's Office."
Terming it as a "very serious matter" and "sabotaging of the investigations", Left parties demanded an explanation from the government and urged the prime minister to order an impartial probe into the issue.
BJP's Deputy Leader in Rajya Sabha Ravi Shankar Prasad said there appears to be a "conspiracy and collusion" in the case of missing files and alleged it was an attempt to protect the prime minister who held the Coal portfolio from 2006-09.
"There has been no response from the government on the coal ministry files which have gone missing. These files are from 2006-09 period. All political recommendations of Congress leaders and crucial files are missing. Records of another 157 private companies are also missing," he said.
"We are legitimately entitled to think that there is a conspiracy and collusion in this case," he added.
Prasad sought to know if there was a conspiracy and said in a criminal case the first step is to remove the witnesses and evidence and the files could have gone missing in an attempt to shield the prime minister and others.
Communist Party of India-Marxist General Secretary Prakash Karat said, "At least 60 files are reportedly missing. It has come to light following the CBI investigations into the coal scam. It is a very serious matter. Many agencies, including the Prime Minister's Office, have been involved (in the files)."
He said the government should explain as to how the files had gone missing. "There are ongoing investigations. We hope the government comes out with an explanation."
CPI MP Gurudas Dasgupta termed the issue as an act of "sabotaging the investigations" into the scam and urged the prime minister to order an impartial probe into the issue.
In a letter to Singh, he said missing of files "cannot be taken to be an innocent act accidentally taking place".
He said it gives rise to serious concern that the files have been deliberately removed "so that people in high positions do not get involved and role of the PMO does not come under shadow of suspicion. It is considered to be a calculative move to exonerate the guilty and cover up the irregularity".
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