In 2023, Eric stumbled upon a disturbing discovery while browsing a social media platform for adult content. A video caught his attention, and within seconds, he was shocked to recognize the individuals on screen.

The footage depicted a couple arriving at a hotel, unpacking, and engaging in intimate activities – a couple that Eric realized was himself and his girlfriend. This revelation was particularly disturbing, as they had stayed at a hotel in Shenzhen, southern China, just three weeks prior, completely unaware of being surveilled.

It became clear that a hidden camera in their hotel room had recorded their private moments, which were then shared with a large online audience, including those who used the same social media channel that Eric had accessed.

Eric, whose name has been changed for anonymity, found himself in the unfortunate position of being both a consumer and a victim of China's clandestine spy-cam porn industry.

Note: The following story may contain language that some readers find objectionable.

The phenomenon of spy-cam porn has been present in China for over a decade, despite the country's strict laws prohibiting the production and distribution of pornographic content.

In recent years, the issue has gained significant attention on social media platforms, with many individuals, especially women, sharing advice on detecting hidden cameras that can be as small as a pencil eraser. Some have taken extreme measures, such as setting up tents in their hotel rooms, to avoid being secretly recorded.

In an effort to address the problem, the government introduced new regulations in April of last year, mandating that hotel owners conduct regular checks for hidden cameras in their establishments.

However, the problem persists, with the BBC World Service uncovering thousands of recent spy-cam videos recorded in hotel rooms and sold as pornographic material on various websites.

Many of these videos are promoted through the messaging and social media app Telegram, where over the course of 18 months, six different websites and apps were found to be advertising their services. Collectively, these platforms claimed to operate over 180 spy-cams in hotel rooms, which were not only recording but also livestreaming the activities of hotel guests.

Over the course of seven months, an observation of one such website revealed footage from 54 distinct cameras, with roughly half of them actively capturing content at any given time.

According to BBC estimates, based on average occupancy rates, it is possible that thousands of individuals were unknowingly filmed during this period, with the majority likely remaining unaware that they were captured on camera.

A man from Hong Kong, identified as Eric, started watching covertly filmed videos in his teenage years, drawn to their unedited nature.

Eric, now in his 30s, explains that the allure of these videos stemmed from the fact that the subjects were unaware of being filmed, stating, "I think traditional adult content can feel very scripted and artificial."

However, Eric's perspective shifted when he discovered a video featuring himself and his girlfriend, "Emily", which led to a loss of interest in this type of content, as he experienced firsthand the other side of the equation.

Emily's initial reaction was skepticism when she was informed that their hotel stay had been secretly recorded, compiled into a one-hour video, and shared on Telegram. However, upon viewing the footage herself, her disbelief turned to embarrassment.

The potential consequences of the video being seen by Emily's colleagues and relatives left her deeply distressed. As a result, the couple ceased communication with each other for several weeks.

The inner workings of the industry, which profits from the unauthorized recording and distribution of intimate moments, raise important questions about its operations and key players.

During the investigation, a notable figure emerged: an individual known by the alias "AKA", who appeared to be a significant player in the spy-cam porn trade.

By posing as a customer, it was possible to gain access to a livestreaming platform promoted by this individual, with a monthly subscription fee of 450 Yuan, equivalent to $65 or £47.

After accessing the system, multiple live feeds from various hotel rooms became available, activated when guests inserted their key cards and turned on the power. Additionally, users could rewind and replay footage from the beginning of the stream, as well as download recorded clips from the archive.

Despite being prohibited in China, Telegram remains a platform of choice for illicit activities, including the promotion of these livestreams by AKA. During the investigation, one Telegram channel associated with AKA had a membership of up to 10,000 users.

AKA also offers compilations of edited livestream clips for purchase on Telegram at a fixed price. The available archive contained over 6,000 videos, with the earliest dating back to 2017.

Subscribers to AKA's Telegram channel engage in real-time discussions while watching the footage of unsuspecting hotel guests, making comments about their physical appearance, speculating about their conversations, and evaluating their intimate activities.

The subscribers often react with excitement when a couple engages in sexual activity, and express disappointment if the lights are turned off, obscuring their view. Female guests are frequently subjected to derogatory language, including terms such as "sluts", "whores", and "bitches".

An investigation led to the discovery of a spy-cam in a hotel room in Zhengzhou, central China, by compiling information from various sources, including subscribers, social media posts, and in-house research.

Upon gaining access to the room, on-site researchers discovered a hidden camera, positioned to capture footage of the bed, concealed within the wall's ventilation system and connected to the hotel's electrical supply.

Utilizing a device designed to detect hidden cameras, a popular tool among travelers, failed to alert individuals that they were being surveilled.

After the camera was disabled, news of the discovery spread rapidly through a Telegram channel.

A message on the primary channel, managed by AKA, announced, "Zhonghua [camera name] has been taken down," prompting a response from a subscriber.

AKA expressed regret in the chat, noting that the room in question had exceptional audio quality.

However, the mood shifted from disappointment to excitement when AKA announced that a new camera had been set up in an alternative location, all within a matter of hours.

AKA highlighted the efficiency of their livestreaming platform, remarking to subscribers, "This is the speed of… [our livestreaming platform]," and invited them to consider its impressiveness.

Our 18-month investigation uncovered around a dozen individuals operating in a similar capacity to AKA.

Through their interactions with subscribers, these agents revealed that they were acting on behalf of more senior figures, referred to as "camera owners," who were responsible for organizing the installation of hidden cameras and overseeing the livestreaming platforms.

In a private conversation, AKA inadvertently shared a screenshot of a message from an individual identified as "Brother Chun", who was referred to as a "camera owner".

After AKA deleted the message and declined to comment further, an investigation led to direct contact with Brother Chun. Despite evidence suggesting his involvement in providing equipment to AKA, Brother Chun described himself as merely a sales agent, while hinting at a more extensive supply chain.

The financial gains from these activities are substantial. According to BBC estimates, AKA has earned a minimum of 163,200 Yuan ($22,000, £16,300) since April of last year, based on channel membership and subscription fees. For context, China's Bureau of Statistics reported an average annual income of 43,377 Yuan ($6,200, £4,600) in the country last year.

Although China has strict regulations governing the sale and use of spy cameras, a visit to the country's largest electronics market in Huaqiangbei revealed that purchasing such a device is relatively straightforward.

Obtaining precise data on the number of individuals prosecuted for spy-cam related offenses is challenging. While Chinese authorities have been less forthcoming with legal case details in recent years, available records indicate that cases have been reported across various regions, including Jilin province in the north and Guangdong in the south.

According to Blue Li of RainLily, a Hong Kong-based NGO that assists victims in removing secretly filmed explicit content from the internet, the organization is experiencing an increase in demand for its services. However, the process of removing such content is becoming increasingly challenging.

Li notes that Telegram does not respond to RainLily's removal requests, which necessitates direct contact with group administrators who are often involved in selling or distributing the explicit material. This approach is often ineffective, as these administrators have limited motivation to cooperate.

Li emphasizes that tech companies bear significant responsibility in addressing the issue of non-consensual content sharing. She argues that these companies are not passive platforms, as their policies play a crucial role in shaping the dissemination of content.

Despite the BBC reporting AKA and Brother Chun's groups to Telegram for sharing spy-cam pornography via its reporting function, the platform took no action. The BBC had informed Telegram about the groups' activities, but there was no response.

When contacted by the BBC again, 10 days later, with a full investigation report, Telegram stated that sharing non-consensual pornography is strictly prohibited by its terms of service. The company claimed to proactively moderate and remove millions of pieces of harmful content daily, and it accepts reports of inappropriate content to facilitate removal.

An official report was presented to Brother Chun and AKA, outlining how they were generating profits by taking advantage of unsuspecting hotel guests. Despite not receiving a response, it was observed that the Telegram accounts used to promote the content were deleted within hours. Nevertheless, the website that AKA had sold access to continues to broadcast live footage of hotel guests.

Eric and Emily are still dealing with the aftermath of their ordeal, which has left them traumatized. As a precautionary measure, they wear hats when out in public to avoid being identified, and they also try to limit their stays in hotels. Eric claims to have stopped using Telegram channels to view explicit content, but he periodically checks them, fearing that the footage of him could resurface.

Additional reporting for this story was provided by Cate Brown, Bridget Wing, and Mengyu Dong.