As a model for the massive Chinese online retailer Taobao, the 31-year-old was well paid to flaunt his good looks in slick promotional videos for clothing brands.
But one video of Mr Ghappar is different. Instead of a glitzy studio or fashionable city street, the backdrop is a bare room with grubby walls and steel mesh on the window. And in place of the posing, Mr Ghappar sits silently with an anxious expression on his face.
Holding the camera with his right hand, he reveals his dirty clothes, his swollen ankles, and a set of handcuffs fixing his left wrist to the metal frame of the bed – the only piece of furniture in the room.
The video of Mr Ghappar, along with a number of accompanying text messages also passed to the BBC, together provide a chilling and extremely rare first-hand account of China’s highly secure and secretive detention system – sent directly from the inside.
The material adds to the body of evidence documenting the impact of China’s fight against what it calls the “three evil forces” of separatism, terrorism, and extremism in the country’s far western region of Xinjiang.
Over the past few years, credible estimates suggest, more than one million Uighurs and other minorities have been forced into a network of highly secure camps in Xinjiang that China has insisted are voluntary schools for anti-extremism training.
Thousands of children have been separated from their parents and, recent research shows, women have been forcibly subjected to methods of birth control.
In addition to the clear allegations of torture and abuse, Mr Ghappar’s account appears to provide evidence that, despite China’s insistence that most re-education camps have been closed, Uighurs are still being detained in significant numbers and held without charge.
It also contains new details about the huge psychological pressure placed on Uighur communities, including a document he photographed which calls on children as young as 13 to “repent and surrender”.
And with Xinjiang currently experiencing a spike in the number of coronavirus infections, the dirty and crowded conditions he describes highlight the serious risk of contagion posed by this kind of mass detention during a global pandemic.
The BBC sent detailed requests for comment to the Chinese Foreign Ministry and Xinjiang authorities but neither responded.
Mr Ghappar’s family, who have not heard from him since the messages stopped five months ago, are aware that the release of the four minute, thirty-eight second video of him in his cell might increase the pressure and punishment he faces.
But they say it is their last hope, both to highlight his case and the plight of the Uighurs in general.
His uncle, Abdulhakim Ghappar, who now lives in the Netherlands, believes the video could galvanise public opinion in the same way that footage of the police treatment of George Floyd became a powerful symbol of racial discrimination in the US.
“They have both faced brutality for their race,” he says.
“But while in America people are raising their voices, in our case there is silence.”
In 2009, Merdan Ghappar – like many Uighurs at that time – left Xinjiang to seek opportunity in China’s wealthier cities in the east.
Having studied dance at Xinjiang Arts University, he found work first as a dancer and then, a few years later, as a model in the southern Chinese city of Foshan. Friends say Mr Ghappar could earn up to 10,000 Rmb (£1,000) per day.
His story reads like an advert for the country’s dynamic, booming economy and President Xi Jinping’s “China Dream”. But the Uighurs, with their Turkic language, Islamic faith and ethnic ties to the peoples and cultures of central Asia, have long been viewed as an object of suspicion by Chinese rulers and faced discrimination in wider society.
Mr Ghappar’s relatives say that Mr Ghappar was told it would be best for his modelling career to downplay his Uighur identity and refer to his facial features as “half-European”.
And although he had earned enough money to buy a sizeable apartment, they say he was unable to register it in his own name, instead having to use the name of a Han Chinese friend.
But those injustices now seem mild by comparison with what was to come.
Ever since two brutal attacks targeting pedestrians and commuters in Beijing in 2013 and the city of Kunming in 2014 – blamed by China on Uighur separatists – the state has begun to view Uighur culture as not only suspicious but seditious.
By 2018, when the state had come up with its answer – the sprawling system of camps and jails built rapidly and extensively across Xinjiang – Mr Ghappar was still living in Foshan, where his life was about to take an abrupt turn for the worse.
In August that year, he was arrested and sentenced to 16 months in prison for selling cannabis, a charge his friends insist was trumped up.
Whether truly guilty or not, there was little chance of an acquittal, with statistics showing that more than 99% of defendants brought before Chinese criminal courts are convicted.
But, upon his release in November 2019, any relief he felt at having served his time was short lived. Little more than a month later, police knocked on his door, telling him he needed to return to Xinjiang to complete a routine registration procedure.
The BBC has seen evidence that appears to show he was not suspected of any further offence, with authorities simply stating that “he may need to do a few days of education at his local community” – a euphemism for the camps.
On 15 January this year, his friends and family were allowed to bring warm clothes and his phone to the airport, before he was put on a flight from Foshan and escorted by two officers back to his home city of Kucha in Xinjiang.
There is evidence of other Uighurs being forced to return home, either from elsewhere in China or from abroad, and Mr Ghappar’s family were convinced that he had disappeared into the re-education camps.
But more than a month later they received some extraordinary news.
Somehow, he had managed to get access to his phone and was using it to communicate with the outside world.
Merdan Ghappar’s text messages, said to have been sent from the same room as his self-shot video, paint an even more terrifying picture of his experience after arriving in Xinjiang.
Written via the Chinese social media app WeChat, he explains that he was first kept in a police jail in Kucha.
“I saw 50 to 60 people detained in a small room no bigger than 50 square metres, men on the right, women on the left,” he writes.
“Everyone was wearing a so-called ‘four-piece-suit’, a black head sack, handcuffs, leg shackles and an iron chain connecting the cuffs to the shackles.”
China’s use of these combined hand and leg cuffs has been criticised in the past by human rights groups.
Mr Ghappar was made to wear the device and, joining his fellow inmates in a caged-off area covering around two-thirds of the cell, he found there was no room to lie down and sleep.
“I lifted the sack on my head and told the police officer that the handcuffs were so tight they hurt my wrists,” he writeas in one of the text messages.
“He shouted fiercely at me, saying ‘If you remove your hood again, I will beat you to death’. And after that I dared not to talk,” he adds.
“Dying here is the last thing I want.”
Abdulhakim says he kept in regular touch with his nephew before he was taken into detention, and he believes – as has been well documented in other cases – that this overseas connection is one of the reasons Mr Ghappar was detained.
“Yes, I am 100% sure about it,” he said. “He was detained just because I am abroad and I take part in protests against Chinese human rights abuses.”
Abdulhakim’s activism, which began in 2009 in Xinjiang when he helped hand out flyers ahead of a large-scale protest in the city of Urumqi, was the reason he fled to the Netherlands in the first place.
The protest in Urumqi later spilled into a series of violent riots which, Chinese authorities say, claimed nearly 200 lives and are seen as another one of the major turning points towards its tightening control over the region.
Told that the Chinese authorities were seeking his arrest, Abdulhakim got himself a passport and left. He has never been back.
He insists that all of his political activities, both inside China and abroad, have been peaceful, and his nephew, he says, has never shown any interest in politics at all.
The list of questions sent by the BBC to the Chinese authorities asked them to confirm whether Merdan Ghappar or his uncle are suspected of any crime in China.
It also asked why Mr Ghappar was shackled to a bed, and for a response from the authorities to his other allegations of mistreatment and torture.
None of the questions was answered.