Freeview is owned by Crown Castle, a television transmission company, and currently maintains 33 channels that are watched by an estimated 2.8 million viewers.
As part of a general marketing campaign to increase conversion rates to digital television from analog, Top-Up TV unveiled a series of new pay channels that take up spare capacity on digital systems, the Guardian Unlimited reports.
The new porn channel will come under the umbrella of the popular Fantasy Channel, one of the most watched adult entertainment digital channels in Britain.
Among the new offerings announced by the network's owner Richard Desmond is Television X, a porn channel that will air between 11 pm and 5 am alongside another channel that is still unnamed.
Top-Up TV is scheduled to air 10 channels for a monthly service fee, with an initial target of 800,000 homes using Freeview set-top digital boxes that can accept a subscription card, the guardian reports. The company is expecting to sign on at least 250,000 new subscribers when it launches.
The network executives at Freeview have distanced themselves from the new digital porn venture, saying that the Fantasy Channel's offerings are "entirely distinct" from Freeview's own offering," the Guardian reports.
"It is a separate company," one executive was quoted as saying. "Freeview will offer free channels and it is really a competitor to cable. I think there will be some people who will want to take that route."