On 6th May 2014, Section 6-A of the Delhi Special Police Establishment Act (DSPEA) 1946, which prohibits investigations without prior approval, was ruled "discriminatory" and "impedes tracking down corrupt senior bureaucrats" by a five-judge constitution bench led by Chief Justice R M Lodha in 2014 in the case of Dr. Subramanian Swamy v. Director, CBI & Anr-W.P. (Civil) No. 38 of 1997 which changed the course of history for the Central Bureau of Investigation. A combined decision of two writ petitions, namely, Dr Subramaniam Swamy v. Director, CBI and Centre for Public Interest Litigation v. Union of India held Sec 6-A to be violative of Article 14 of the Constitution on the principle of ‘Equality before Law’. Since Section 6-A came to be inserted by Section 26(c) of the Central Vigilance Commission Act, 2003, the constitutional validity of Section 26(c) has also been raised. 

Before insertion of Section 6-A in the Act, the requirement to obtain prior approval of the Central Government was contained in a directive known as “Single Directive” issued by the Government. The Single Directive was a consolidated set of instructions issued to the Central Bureau of Investigation (CBI) by various Ministries/Departments regarding modalities of initiating an inquiry or registering a case against certain categories of civil servants. The Single Directive was quashed by this Court in Vineet Narain & Ors. v. Union of India & Anr [(1998) 1 SCC 226)]. In this case the Supreme Court emphasized on the point that the directive would be applicable if the investigation of the offences was being done by the Central Bureau of Investigation and would not have any application on the exercise of power by the state police. Subsequent to this judgement Sec 6-A was inserted by the Central Vigilance Commission Ordinance, 1998. In 2003, the Central Vigilance Commission Act came into existence and as per the Act, a Central Vigilance Commission was constituted to conduct inquiries into offences alleged to have been committed under Prevention of Corruption Act, 1988. Section 26(c) provides for the insertion of section 6-A into the Delhi Special Police Establishment Act, 1946. Sec 6-A of Delhi Special Police Establishment Act says that the Delhi Special Police Establishment shall not conduct any inquiry or investigation into any offence alleged to have been committed under the Prevention of Corruption Act, 1988 except with the previous approval of the Central Government. Therefore, this provision restores the law to what it was before when the Single Directive applied to offences committed under the Prevention of Corruption Act, 1988.

Mr. Anil B Divan, the learned Amicus Curiae argued that the provision in question undermines the rule of law as explained in the Vineet Narain case and the principle of independent, unhindered, unbiased, and efficient investigation. He contended that prior sanction would result in indirectly putting to notice the officers to be investigated before commencement of investigation. He also referred to N.N. Vohra Committee report which paints a frightening picture of criminal-bureaucratic-political nexus – a network of high level corruption – and submitted that the impugned provision puts this nexus in a position to block inquiry and investigation by CBI by conferring the power of previous approval on the Central Government. He vehemently contended that  that the classification as contained in Sec 6-A creating a privileged class of the government officers is directly destructive and runs counter to the whole object and reason of the Prevention of Corruption Act,1988. Therefore, in light of the corruption prevalent in the country the impugned provision is completely irrational and arbitrary. 

On the other hand, though Mr. L. Nageswara Rao, the Learned Additional Solicitor General, concedes that corruption is on the rise and that investigative agencies should be free from extraneous interference, he maintains that a law cannot be struck down on the basis of arbitrariness or unreasonableness because such a ground is only available to quash executive action and orders. He further submits that Section 6-A satisfies the test of reasonable classification. The public servants of the level of Joint Secretary and above take policy decisions and, therefore, there is an intelligible differentia. As they make policy decisions, there is a need to protect them from frivolous inquiries and investigations so that policy making does not suffer. Thus, there is a rational nexus with the object sought to be achieved.

The Supreme Court bench observed that the criminal justice system mandates that any investigation into the crime should be fair, in accordance with law and should not be tainted. It is equally important that interested or influential persons are not able to misdirect or hijack the investigation so as to throttle a fair investigation resulting in the offenders escaping the punitive course of law. These are important facets of rule of law. Breach of rule of law, amounts to negation of equality under Article 14. It is obvious that the  classification which is made in Section 6-A on the basis of status in the Government service is not permissible under Article 14 as it defeats the purpose of finding prima facie truth into the allegations of graft, which amount to an offence under the Prevention of Corruption Act, 1988. Section 6-A fails in the context of these facets of Article 14.  

The bench also emphasized that the essence of police investigation is skillful inquiry and collection of material and evidence in a manner by which the potential culpable individuals are not forewarned. If the CBI is prevented from conducting a preliminary investigation, a shackle is placed on the CBI's ability to gather relevant information. As a matter of fact, the CBI won't even be capable of obtaining the material necessary for a prior approval from the Central Government. Having considered the contentions, it was held that section6-A is invalid and violative of Article 14 of the Constitution. As a necessary corollary, the provision contained in Section 26(c) of the Central Vigilance Act 2003 to that extent is also declared invalid.