Sharma, a property dealer, had carried out sting operation between 2008 and 2010 and secretly filmed a number of Delhi Police and MCD officials allegedly taking bribes across the national capital territory.
CBI has registered a case under provisions of Prevention of Corruption Act against unknown officers of Delhi Police and the civic body.
The probe was initially handed over to Delhi Police but there was considerable delay of over two years, despite clear orders of the Delhi High Court.
CBI had claimed reservations on taking up the probe saying the investigation is at the tail end by Delhi Police which was rejected by the Delhi High Court.
Sharma had carried out sting operation at 30 points in the national capital and a number of traffic police personnel were caught on camera allegedly accepting bribes from Blueline bus operators.
Besides this, he had also conducted sting operations on MCD officers and allegedly captured their audio-video recordings while taking bribe from public.
Handing over the probe to CBI, the high court had said "several facets and aspects stated by the status report (filed by Delhi Police) make us both sceptical and disillusioned, if not frustrated and exasperated.
The Vigilance inquiry had concluded that prima facie case
was made out under the PC Act against 21 police personnel, it had noted.
"It is disturbing to note that most of the public witnesses are not traceable, or when traceable have refused to give statements. Failure to locate or trace public witnesses is a matter of concern. Delay and holdover in the registration of the FIR for about two years and subsequent investigation could be the reason and cause," it said.
In a terse order, the High Court had said other possible causes for the failure to locate and trace witnesses could be that the names and other details provided are false, or that the investigating agency is choosing to hinder and protect.
"We are not expressing any opinion on this aspect, suffice to say that failure to locate and trace witnesses reflects on the efficacy and vigour of the investigation. The investigation, it appears has faulted," it had said.
The Court had said the investigation has struggled, has become bedraggled, and has not proceeded meticulously and punctiliously, as was required and necessary, when stated incidents of corruption and bribes were captured live on recording media.
It said the persons allegedly involved are not one or two but numerous police officers, who are meant to check crime and enforce the law.
"Apparently, the primary investigation has revealed the commission of offences by a number of officers taking bribes. It is difficult to appreciate and understand why it has taken more than six years after the order dated 28th July, 2010 to complete investigation and file the charge sheet," the HC said in its November last order.