TNL Chairman Shan Wickremesinghe said he would sue the Telecommunications Regulatory Commission (TRC) for sealing the transmission centre owned by TNL.
Speaking to Asian Mirror, Wickremesinghe said although he tried to contact a senior official from the TRC, no one responses to his phone calls.
It is learnt that plans are afoot to close down several other transmission centres owned by the TV network.
The TNL group is owned by Prime Minister Ranil Wickremesinghe's elder brother Shan Wickremesinghe, a pioneer in the Sri Lankan television industry.
The TV station, in a Facebook post, confirmed that its transmission centre in Polgahawela had been sealed by the TRC.
The TRC comes under the purview of President Maithripala Sirisena and President's Secretary Austin Fernando functions as its Chairman.
The move comes in the wake of a new segment run by the Television station, criticizing a recent speech made by the President.