He said the development was already known to relevant security agencies, adding that currently the NBC and other relevant bodies had not been able to block it as the station transmitted via international transmission system.
He spoke during an interactive session with journalists in Ilorin, the Kwara State capital, on Tuesday.
The NBC DG also said Boko Haram insurgents had commenced radio transmission with their station located between Nigerian and Cameroonian borders.
He, however, said security agencies were notified and the station had been stopped from transmission.
He warned against subversive transmission, adding that such an unlawful act could threaten the corporate existence of Nigeria.
Kawu reiterated the commitment of the NBC to ensuring that all TV and radio transmissions in the country complied with relevant NBC codes.
He said, “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 1960s and abusing everyone.
“Now, this is happening and they were asking us (NBC) and they would ask us 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 said the NBC was facing a major difficulty in trying to regulate what people broadcast, stressing that the stations felt that the more outlandish their claims were, the more popular they would become.
He warned the owners of TV and radio stations to renew their licence fees, adding that licences were provisional and could be withdrawn at any moment.
He said, “They owe us a lot of money, about N5bn. They are negotiating with us along with the Broadcasting Organisation of Nigeria and we have given them a three-month grace because our patience is not limitless. It will get to a time when we will have to close many stations in Nigeria, not because of what they say but for not paying our fees.”