A judge has ordered all videos featuring popular animated character Wolfoo to be removed from platforms including YouTube after ruling that the cartoon illegally copied audio from Peppa Pig.

Wolfoo, a Vietnamese animation about a young wolf who lives with his family, has had hundreds of millions of views online.

A High Court judge in London recently ruled in favour of entertainment giant Hasbro, which owns the rights to Peppa Pig, after it sued Wolfoo’s makers SConnect for copyright infringement.

Mr Justice Smith said the copying – in which Wolfoo videos used short audio clips of Peppa and her family saying words like “hooray!” – had been “prolific” and “long-standing”.

In a ruling this week, the judge said “all videos featuring Wolfoo” must be taken down before 16:00 BST on Monday.

Hasbro and Peppa Pig’s creators Astley Baker Davies Ltd originally took court action in London in 2022.

They claimed SConnect had attempted “to deceive the young Wolfoo viewership, most aged between two and five, into believing that Wolfoo is the same character as Peppa Pig” or connected to Peppa, the judge wrote.

The companies initially complained about Wolfoo’s appearance and artwork, but focused their legal case on the audio because they believed it would be easier to prove that sound clips were directly copied.

The evidence of “copying of the audio clips is compelling”, the judge decided.

“That copying was extensive, seemingly endemic at least so far as the English language Wolfoo videos are concerned.”

SConnect denied the copyright infringement claim but accepted that some Wolfoo videos made before mid-2020 included audio from Peppa Pig because an independent third-party contractor had used the clips without the company’s knowledge.

SConnect said all infringing videos were removed, and that Wolfoo animations made after mid-2020 used only voices and sounds that were created in-house.

However, the judge said the fact the sounds were supplied by a third party was “irrelevant”; that while many infringing videos were removed, some were simply moved to other channels; and that the claim that all new sounds were recorded in-house “can be disproved”.

BBC News has asked SConnect for comment.

The judge said clips from Peppa Pig were found in all 92 English-language Wolfoo videos that were examined, and about 75% of the foreign-language videos.

SConnect said the ruling should only apply to the videos examined in the sample, but the judge declared that all Wolfoo videos should now be removed.

SConnect also argued that the area covered by the ruling would be “too broad”, but the judge said it would apply in the UK, European Union and all 166 World Trade Organisation member states, which also include the USA and Vietnam.

Andrew Lee, partner and head of intellectual property at law firm Brandsmiths, which represented Hasbro, told BBC News it was a “significant judgment”.

Peppa Pig is available “in hundreds of countries around the world, and this was obviously a major problem for the brand because of the scale of Wolfoo”, he said.

“By bringing the claim in the UK courts, which was our home territory, and because the defendants had activity in the United Kingdom even though they were based in Vietnam, we were able to persuade the court to hear the case on a wider scale.

“So it was about trying to protect the Peppa Pig brand in one forum, rather than having to bring actions in every single country.”