Ofcom has told TVBEurope it is "concerned" at the on-going row between Virgin Media and UKTV.
An estimated four million Virgin Media customers lost access to UKTV's channels yesterday.
In a statement, Ofcom said: "We are always concerned that consumers are treated fairly and their interests are protected. If customers are unhappy with a change to their service, they should raise concerns with Virgin Media in the first instance.
"We would also consider any complaints we receive.”
In its own statement on the row, UKTV highlighted the fact Virgin Media had increased subscriber fees last year: "The two companies were unable to reach an agreement on a new distribution deal after Virgin Media demanded a huge cut in the fees paid to UKTV. Since the news broke last week hundreds of Virgin Media customers, who faced an increase of up to £48.00 in their annual subscription last November, have taken to social media to express their unhappiness about losing their favourite channels."
"Prior to the switch-off, UKTV's channels were some of the most popular on the Virgin Media platform. Alibi and Gold were two of Virgin's top three pay entertainment channels, while Good Food was the top pay lifestyle channel. Overall, UKTV accounts for more than a quarter of all viewing to pay entertainment channels in Virgin's basic pay TV package and its on demand views grew by more than a third in the last year," continued the statement.
Virgin said on Twitter that it is still in discussions with UKTV.