Pornhub, along with three other major pornography websites, is being investigated over suspicions they have breached the bloc's online content rules which include provisions for protecting children from the explicit material.
The European Commission, the EU's executive branch, said it had opened formal proceedings against Pornhub, Stripchat, XNXX and XVideos under the 27-nation bloc's Digital Safety Act.
The sweeping rulebook, also known as the DSA, requires internet companies and online platforms to do more to protect users, under threat of fines worth up to six per cent of annual global revenue.
The commission said protecting young users online was one of the DSA's priorities and it would now carry out an in-depth investigation into the companies 'as a matter of priority'.
The investigation would focus on the risks to protection of minors, including dangers associated with the lack of effective age verification measures.
