Beijing police have arrested five people they say played a role in the filming of a video of a couple having sex in a Uniqlo fitting room in China’s capital.

The sheer number of people involved in the video, which has gone viral on social media networks around the world, has raised speculation the apparel retailer was somehow involved behind the scenes in engineering the video as a publicity stunt.

But the company has strenuously denied it had anything to do with the one minute long production, or endorses it. And such a viral campaign certainly does not fit with the company’s ethical positioning or its record of community involvement and sponsorships.

Some Chinese media say the police “suspect that the case may possibly be a publicity stunt by Uniqlo”, one going so far as to quote a Beijing lawyer saying the company could face a fine of between 200,000 and 1 million RMB (US$32,000 and $165,000) and have its trading licence revoked if it was found to be involved.

In a statement (not issued through Uniqlo’s normal media media channels) Uniqlo reportedly condemned the filming.

Since the video was uploaded, attracting attention from news organisations worldwide, the Sanlitun flagship in which it was filmed has become something of a tourist attraction, with people posing for photographs outside.

The young couple who had reportedly “only just met” were quickly identified via social media and have become celebrities on Chinese social media networks, albeit they have now reportedly been arrested and charged with indecency.

From censored stills posted online by news media outlets, the video appears to have been filmed entirely by mobile phone. So the involvement of an additional three people is puzzling unless they were responsible for its spread or reposting, rather than production as reported in China.

Meanwhile, Chinese authorities have summoned representatives of Tencent and Weibo to discuss how the video was so widely shared and viewable on its networks. Chinese law prohibits pornography.