The OCI Tracker Benchmark Study, carried out by Kantar Media, found that one in six believed they had downloaded or access content illegally over a six month period.
The ongoing research is part new responsibilities given to the regulator under the Digital Economy Act 2010 to report to government on efforts made by content owners to educate consumers about the impact of copyright infringement. It will cover TV, film, music, software, books and video games.
Ofcom says that the 47% that could not confidently identify whether the content they had viewed was illegal or not, highlighted the importance of educating and informing the consumer.
The most common reasons cited for accessing content illegally were because it is free (54%), convenient (48%) and quick (44%). Around a quarter (26%) of infringers said it allows them to try before they buy.
Users that consumed a mix of legal and illegal online content, particularly music, film and TV, were found to be spending more on legal content than those who viewed legal or illegal content alone.
According to Ofcom, consumer research is only one perspective on levels of online copyright infringement. It should be considered alongside direct measurement of behaviour on file-sharing websites and wider industry data.