Is'haq Kawu, director-general of National Broadcasting Commission (NBC), says a radio station owned by the Boko Haram sect has been blocked and efforts are being made to shut Biafra Television, purportedly owned by the Indigenous People of Biafra (IPOB).
He made this known at an interactive session with journalists in Ilorin, Kwara state capital.
Kawu said Boko Haram commenced its broadcast via a station located between Nigerian and Cameroonian borders.
He also explained that the difficulty in shutting the Biafran station is because of the international transmission system which the station is using.
Kawu warned against revolutionary transmission that could threaten the Nigeria's unity.
"Last week, I was in the office of the inspector-general of police and they had a TV screen and what was being broadcast was on Biafra Television; they were saying some of the most outlandish things, showing videos from the 1960 s and abusing everyone," he said.
"Now, this is happening and they were asking us (NBC) because our duty is to monitor and regulate such but the television is coming from outside of Nigeria.
"Our engineers have been making contacts with the international satellite organisation that does broadcast to Africa about the fact that you cannot allow subversive broadcast into Nigeria from other parts of the world.
"The Biafra Television in the south-east, we have been tracking the station. The broadcast is coming from outside Nigeria. We have been asking questions from international satellite test systems where they are coming from. That is how it is for now.
"Last June, Boko Haram was starting a new radio station, I think on 91 .00 megahertz on the FM band from the border between Nigeria and the Republic of Cameroon and so it was our duty to inform security organisations what was happening so they could take it up and which they did eventually."
He further said the commission is currently owed about N3bn and that stations yet to pay their fees risk getting shut down.