Nageswar Rao, a 1986-batch officer, had joined the CBI in 2015.

Highlights CBI was headed by Anil Sinha when Nageswar Rao joined in 2015

Special Unit tabled report on Mr Rao on corruption charges against him

Assessment ignored by Mr Sinha as well as the government

In "cleaning up" the country's top probe agency, the Central Vigilance Commission (CVC) shunted out two top officials facing charges of corruption and appointed Nageswar Rao -- a relatively junior 1986-batch bureaucrat -- as the interim chief of the CBI. However, NDTV has now found that the new director has a chequered past himself.

The CBI was headed by Anil Sinha when Mr Rao joined in 2015. Amitabh Singh Dhillon, the head of the agency's counter-intelligence unit or Special Unit, had then tabled an adverse report on Mr Rao -- saying that he should not be inducted on the grounds of corruption charges levelled against him and his alleged proximity to political parties. However, the assessment was ignored by Mr Sinha as well as the government.

The corruption charges were related to the purchase of State Bank of India land by VGN Developers, a Chennai-based firm. According to the complaint, Mr Rao -- who was the then Chennai Zone head -- had not hauled up the accused despite the land being sold at a loss to the exchequer. This was one of the reasons for DMK leader MK Stalin criticising his elevation to the post of CBI Director.

This, however, is not the only complaint filed against Mr Rao.

While Mr Rao was serving as a joint director in the CBI earlier this year, a file titled "Premature repatriation of Shri Nageswar Rao, IPS'' (File no 202/01/2015) was sent to the Cabinet Committee on Security. It suggested that the official be sent back to Odisha in the light of several complaints, one of which he allegedly closed down in connivance with a senior Delhi official. According to the complaint, Mr Rao had allegedly tried to stall the probe against over 70 Income Tax (I-T) officers listed in arms dealer Sanjay Bhandari's diaries. Police had arrested Mr Bhandari along with I-T Joint Commissioner Sallong Yaden in January 2015, and incriminating evidence against several officials was allegedly recovered from his possession. Incidentally, the ruling BJP has accused Mr Bhandari of being close to Robert Vadra, son-in-law of Congress leader Sonia Gandhi.

Mr Rao is also accused of misrepresenting facts in his annual tax returns. All his assets filings post-2010 show a Rs 20-lakh property owned by his wife and her cousin in Guntur, Andhra Pradesh. The cousin -- Dr Ratna Babu -- was later revealed to be the brother of his wife, Chinnam Sandhya.

Although senior lawyer Prashant Bhushan posted some of these allegations on Twitter, the CBI has refused to react. NDTV reached out to the CBI for a reaction, but did not get one.