NEW DELHI: With court-mandated investigations into 2G and Coalgate scams seen to have hurt his government's image, Prime Minister Manmohan Singh on Monday suggested the Central Bureau of Investigation should probe policy matters with considerable caution.

Singh's words to advice to CBI are similar to the government's view on the Comptroller and Auditor General reports on 2G where it clashed with the auditor's interpretation of its mandate to evaluate whether a particular policy prescription resulted in loss of revenue.

The PM's comments also come soon after CBI booked industrialist Kumar Mangalam Birla and former coal secretary P C Parakh in a coal allocation case that Singh had approved during UPA-1, bringing the controversy right to his doorstep.

Addressing close to 1,000 CBI officers, investigators from 19 foreign countries, representatives from states and other agencies, Singh said "some decisions which appear sensible ex-ante may ex-post turn out to be faulty" and "errors of judgment are distinguished from criminal acts".

In his speech, CBI director R C Sinha said quick decisions were needed for economic growth but the process should be such that reduces scope for impropriety.

Last month, after CBI registered its 14th FIR in the coal scam against the Aditya Birla group chairman and Parakh alleging that the government had altered a decision to favour Hindalco, the PM had defended the allocation, calling it "appropriate" and "done on merits".

Singh held that errors of judgment should be distinguished from a criminal act, adding that it would not be appropriate for a police agency to sit in judgment over policy formulation, without any evidence of malafide.

"Over time, investigating agencies in our country have been increasingly enquiring into administrative decisions and also matters related to policy making. Such cases require great care in investigation. While actions that prima facie show malafide intent or pecuniary gain should certainly be questioned, pronouncing decisions taken with no ill-intention within the prevailing policy as criminal misconduct would certainly be flawed an excessive," Singh said.

"Policy-making is a multi-layered and complex process in the government, and will increasingly become more so, and therefore I don't think it would be to appropriate for a police agency to sit in judgment over policy formulation, without any evidence of malafide," he added.

The PM said lines of confidence must be clearly drawn between investigating agencies on the one hand and honest executive functionaries on the other so that public servants may not be paralyzed in taking effective decisions based on their own sound judgment and on the apprehension of an ill-informed inquiry or investigation.

CBI director Ranjit Sinha said while quick decisions were needed for fast economic growth, it should be done in a manner where there was no scope for impropriety. Sinha said allocation and acquisition of natural resources was a "particularly contentious issue" in the current Indian and global context.

"While there is a need for fast economic growth necessitating need for quick decisions on exploitation of natural resources, the challenge for policy makers is to do it in a manner that there is no scope for impropriety," Sinha said. CBI is probing a number of cases related to allocation of natural resources like coal and natural gas.

Singh, in his speech, also said that charge-sheets must be filed after going through rigorous scrutiny. "A trained mind is necessary for discovering criminality. When a charge-sheet is filed, the charge-sheet must go through rigorous process of scrutiny and there must be a high chance of securing conviction in that case," he said.

The PM said there was a need for greater professional expertise in the CBI, including from non-police organizations. "I have touched upon this subject earlier also but this is something that is well worth repeating," he said.

Singh said the fact that economic growth also implies greater opportunity for corruption was often forgotten in public debates on graft. "We can't be all the time just running down institutions of governance because there have been cases of wrongdoing," he said.

Inaugurating the CBI's International Conference on Evolving Common Strategies to Combat Corruption and Crime, PM also released a commemorative stamp on the Golden Jubilee of CBI.