On June 2, an FIR was lodged by CBI alleging criminal conspiracies, cheating by NDTV and unknown officials of ICICI Bank about "something that took place during 2008-09", he said.
"Why was it not brought to light earlier was not mentioned anywhere," he said.
Mr Nariman said the FIR was filed by the CBI on the basis of a single complaint and not based on any discovery.
"The FIR was filed solely on the information provided by a private individual."
The jurist emphasised that the CBI instituted a criminal inquiry against Dr Roy immediately after receiving the complaint.
"It should have told the complainant to file a complaint in a criminal court but rather the raids took place and were carried out as widely publicised," he said.
"We citizens enjoy freedom, which is not there in many places in the world. There is a freedom of speech guaranteed in the constitution," he added.