Half the adult population of the UK watched online pornography during the pandemic, according to a projection by Ofcom which lays bare the activities of the 26 million individuals who view adult material.

By far the most popular pornography site was PornHub, which was visited by 50% of all males and 16% of all females in the UK in September 2020 – giving the site a far larger audience than mainstream television channels such as Sky One, ITV4 and BBC News.

The figures rise substantially among younger age groups, with a third of young women and three-quarters of young men visiting PornHub in the four weeks covered by the research. Ofcom also quoted PornHub’s own claims that the average UK visitor spent 10 minutes and 20 seconds on the site – an attention time that would be envied by many mainstream outlets.

The figures were contained in Ofcom’s annual report on the country’s online media consumption habits, which has traditionally focused on mainstream sites such as Facebook and YouTube. But this year the regulator decided to broaden its research to include pornography because many adult sites are likely to come under Ofcom’s responsibilities as part of forthcoming plans to regulate video-sharing platforms and oversee online safety.

Despite the growth of online pornography in the UK, the sector remains lightly regulated with little public understanding of the large and very profitable companies that run the leading sites. Three of the most popular pornography sites in the UK – PornHub, Redtube, and YouPorn – are owned by a single Canadian company called MindGeek.

Many of these companies have gone to great lengths to conceal their identity, with the ultimate owner of PornHub being publicly unveiled as Bernard Bergemar only at the end of last year. He was identified shortly after his site was forced to delete tens of millions of videos following an outcry about the presence of revenge porn: videos remaining on the site featuring people who had not consented to them being posted.

Ofcom also highlighted the growth of the British-headquartered website OnlyFans, which allows individuals to sell their own homemade pornography online. The site has proved to be wildly profitable for the Essex family who founded the site in 2016.

Ofcom said: “It has been reported that economic factors caused by the lockdowns may have led people to turn to sites such as OnlyFans to generate an income, in the context of rising unemployment or furlough, and financial uncertainty for many in the UK.”

Two years ago the government abandoned plans to introduce mandatory age checks on individuals viewing adult sites, which could have required people to buy a verification code from their local newsagent.

The Ofcom research also found that people were increasingly living their lives online, with the average UK adult spending more than three and a half hours online each day in 2020, an hour longer than in Germany and France and 30 minutes more than Spain.

Yih-Choung Teh, Ofcom’s director of strategy and research, said: “In an unprecedented year, we’ve seen a real acceleration in our migration to online services – which, for many people, have provided a lifeline in lockdown. This research is critical to keep pace with these changes in technology, economics and behaviour, as we prepare to take on new responsibilities for regulating online safety.”