The Central Bureau of Investigation has initiated a preliminary inquiry into the alleged irregularities in the construction and renovation of Delhi Chief Minister Arvind Kejriwal’s official residence, The Indian Express reported on Thursday.

A preliminary inquiry is the first step in the central agency’s investigation, based on which a decision to file a first information report is taken. The inquiry has been filed against “unknown public servants of the Government of Delhi”, according to NDTV.

The Central Bureau of Investigation has asked the Delhi government’s Public Works Department to share certified copies of approval plans, payment vouchers and other documents related to the project by October 3.

The development comes two months after the Bharatiya Janata Party-led Central government had asked the Comptroller Auditor General of India to conduct a special audit into the alleged irregularities and violations in the reconstruction of Kejriwal’s home.

The direction was issued after the Ministry of Home Affairs took note of a letter sent by Lieutenant Governor VK Saxena on May 24.

In the letter, he had said that the “irregularities” in the reconstruction were first highlighted by the media following which the Delhi chief secretary was asked to submit a report. The chief secretary, in his report, had claimed that the initial cost for construction work at Kejriwal’s home was projected to be between Rs 15 crore to Rs 20 crore but it had been “inflated from time to time” till it reached Rs 52 crore.

On Thursday, Kejriwal said that he welcomes the inquiry as no evidence of any illegal activity would be found, reported India Today. “Kejriwal will not bow down no matter how many fake investigations are initiated,” he said.

The chief minister also alleged that the action shows that Prime Minister Narendra Modi is nervous.

“This is not the first inquiry,” Kejriwal added. “They have already initiated more than 50 enquiries. Sometimes they will say there was corruption in the liquor policy, other times, it’s the buses, the schools or the roads.”

The Aam Aadmi Party on Tuesday had described the move as a desperate attempt by the BJP to malign it.

“All the investigating agencies have been deployed to corner Delhi Chief Minister Arvind Kejriwal,” the party said in a statement. “But the love and blessings of two crore people of Delhi are with him. Till now investigating agencies have filed more than 50 cases against him but they amounted to nothing. Nothing will come out of this either.”