Delhi Deputy Chief Minister Manish Sisodia on Friday filed an RTI to get details about the expenditure incurred on Prime Minister Narendra Modi's digital and other social media campaign.

The Aam Aadmi Party (AAP) leader said he was taking recourse to RTI as the Modi government was unleashing the Central Bureau of Investigation (CBI) against the Delhi government to get similar information.

"If Modiji has CBI, we have RTI (Right to Information)," Sisodia told reporters here.

Sisodia's RTI comes after the CBI registered a preliminary inquiry against him last month to probe alleged irregularities in the "Talk to AK" social media campaign.

Backing his deputy, Delhi Chief Minister Arvind Kejriwal said the CBI should investigate Modi as well.

"Just like Prime Minister's Office awarded contracts for digital advertisements, Manish (Sisodia) awarded advertisements in the same way.

"Since Modiji is getting Manish investigated by the CBI, he (Modi) should be investigated by the same agency as well," Kejriwal tweeted.

In his RTI, Sisodia sought details of the procedures adopted by the central government to award social media advertisement contracts for Make In India, Namo App, Start-up India and Digital India.

"Advertisements in social media are paid for by credit cards and have a credit limit. Which credit card was used by the Modi government for these advertisements?" Sisodia asked.

He also asked for details of companies and individuals across the world awarded the contracts for the advertisements.

"When we talk about people's issues, it is corruption. When he (Modi) talks (Mann ki Baat), it is patriotism. Why this difference?"

Sisodia said if Modi had the CBI to seize files of the Delhi government, then he (Sisodia) would use RTI to access files from the Prime Minister's Office.

"We will place both files before the people and they will decide who is using public money for the right purpose and who is misusing it."

The "Talk to AK" campaign was an interactive session of Kejriwal, under which people could reach out to the leader through social media.