The Delhi cabinet, headed by Arvind Kejriwal, is also likely to be dragged into the Central Bureau of Investigation's (CBI) probe into allegations of irregularities in a government-led social media campaign. The CBI had already initiated a probe against Delhi Deputy Chief Minister Manish Sisodia on Thursday.

Top CBI sources claimed that the contract for the campaign was cleared by the state cabinet even after being flagged thrice by different departments of the Delhi government.

According to sources privy to the case history, an ex-post facto approval in connection to the under-scanner social media campaign was passed by the state cabinet and signed by the Delhi CM himself in the first week of September.

The approval, which sought to seek permission post an order, was approved by the cabinet on September 2, 2016 – nearly two months after an order awarding the work to a Delhi-based private firm.

The contract was to carry out a social media campaign named 'Talk to AK', an idea conceived along the lines of PM's 'Mann Ki Baat'. Delhi-based public relations firm Perfect Relations Pvt Ltd, which was hired by the government as a consultant, had allegedly quoted Rs 1.05 crore and it was approved by the state cabinet.

Elaborating on the sequence of events, a CBI official said the proposal to carry out the campaign was made by Perfect Relations and approved by Sisodia's office, which had hired the firm as a media advisor.

"But soon after the proposal had come to the Delhi government, then Principal Secretary (Finance) raised objections on July 16. Sometime later, the information and publicity department also raised concerns. The files were, however, moved even after the principal secretary (finance) raised concerns for the second time in July," said a CBI source.

According to the source, the main contention then was the awarding of the contract on a single nomination basis, which was a violation of rules and regulations.

The firm went on to buy advertisement space on social networking websites such as Google, YouTube and Facebook, a CBI official told DNA. "This was when approval was sought even as objections were raised by some departments within the Delhi government, thus creating a liability on the state government," the official told DNA.

Sources now say that the Delhi Deputy CM might soon be approached and documents would be sought from the AAP-led government, an eventuality which could further flare up the situation between the Centre and the Delhi government. Furthermore, officials privy to the investigation told DNA that the ex-post facto approval by the cabinet led by Kejriwal will also be a part of the investigation as it has already been mention in the PE registered by the CBI on Wednesday.