The party also asked the government to register an FIR (First Information Report) with police on "stolen/missing" files.
In a joint statement, Sushma Swaraj and Arun Jaitley, leaders of opposition in the Lok Sabha and the Rajya Sabha, respectively, said the coal allocation scam was becoming "murkier and murkier".
They said the prime minister, in charge of coal portfolio between 2006 and 2009, in his statement in parliament Tuesday was not even willing to acknowledge the reality of missing files.
The BJP leaders said, "The failure of honourable prime minister to acknowledge the factum of missing files... the defiance of the authority of the Supreme Court by the government, the presentation of half-baked facts by the coal minister, all point to the fact the government does not want the truth to come out."
The statement said a news report appearing in a newspaper Wednesday said Senior Superintendent of Police K.R. Chaurasia, on perusal of the material collected during investigation, desired that Manmohan Singh, in charge of the coal ministry between 2006 and 2009, required to be questioned.
The BJP leaders said the suggestion of the official has so far not found favour with the higher-ups in the Central Bureau of Investigation (CBI).
They said the official's suggestion was critical to the investigation and a substantially large number of documents connected with "the coal block allocation scam" have disappeared.
Jaitley and Swaraj said: "We are constrained to demand the government confirm or deny the fact that the investigating officer has required the examination of the prime minister on basis of the material before him so that no further tampering and doctoring of the investigation takes place."
"The material on basis of which he requires the examination of the prime minister should also be publicly disclosed. The reasons on basis of which the prime minister's examination is not being permitted should also be made public."
They said the government must register an FIR on the missing documents and explain reasons why it has not been done so far.
The leaders alleged the files "were made to disappear".
"The oral examination is not being permitted. It seems that the effort of the UPA (United Progressive Alliance) government is to sabotage the investigation and render it ineffective," the two BJP leaders said in the statement.
"The screening committee acted as per the dictates of the powers that be. The prime minister acting as the coal minister and the Prime Minister's Office approved the list of favourites arbitrarily chosen," the statement said.
It said parliament was initially misled so as to create an impression that only pre-2004 files are missing.
"It now transpires that a large number of files which pertain to allocation between 2006 and 2009 are also missing. The disappearance of the files, the doctoring of the status report at the behest of a minister and officials of the PMO (Prime Minister's Office) have been the hurdles which the government has tried to create in the honest conduct of investigation," the statement said.
The BJP leaders said Coal Minister Sriprakash Jaiswal had made two statements before parliament which fall short of making a complete and honest disclosure.
"The prime minister is not available for answering questions before parliament and when the investigating officer from CBI wants to examine the prime minister, he is presently not permitted to do so. The casualty in the process is the discovery of truth with regard to the coal block allocations," the statement said.
--IANS (Posted on 04-09-2013)