The probe has been initiated under the provisions of the Prevention of Money Laundering Act (PMLA), the official said, adding it is related to the ED's investigations in connection with "foreign funding" transactions of the entity.
More details about the exact charges being probed by the agency were not available as the official said the case is sub-judice.
The NDTV, meanwhile, alleged "intimidation of epic proportions" by central probe agencies in the last 24 hours.
It said the three central agencies-- the CBI, the ED and the Income Tax Department are "attacking NDTV over one transaction in which GE, USA, made a $150 million investment in NDTV--a perfectly legitimate and publicly, officially declared investment-which they are calling a 'sham transaction'."
"India-and the world-is watching this witch hunt against independent media. It will irreversibly hurt India's reputation as a democracy with a flourishing and free press.
Especially shocking is a demand of Rs 429 crore from the Income Tax Department. The department's letter, sent today, says NDTV has to pay the amount 'immediately now' (sic!)," it said in a public statement.
It added that a demand "for immediate payment without any notice period is unheard of and smacks of sinister motives by the IT Department.
NDTV will not take such arbitrary and illegal action lying down and will take appropriate action in the matter," it said.
The channel said the CBI is indulging in an "undisguised fishing expedition" and it has sent a letter "demanding documents from the NDTV and its subsidiaries for an unspecified period- this despite NDTV having supplied more than 500 pages of documents only two weeks ago.
"Strangely, the CBI does not acknowledge the receipt of these documents.
"Separately, the Enforcement Directorate informed the Bombay High Court yesterday that it is investigating NDTV for violations under PMLA- it has never, of course, informed NDTV of any such charge.
'The ED has already spent a good part of the year summoning NDTV management and questioning them repeatedly, without informing the company of what it has done wrong," it said.
"The government is making clear the implications of fearless journalism. Despite the illegal and massive pressure, NDTV will not allow its coverage to be affected by these shameful tactics."
The CBI, last month, had searched the residence of NDTV founder Prannoy Roy here after registering an FIR for causing an alleged loss of Rs 48 crore to ICICI Bank in a loan resettlement in 2009 and concealing from the SEBI and stock exchanges the pledging of shares for the loan.