The disappearance of tennis star Peng Shuai in China following her accusation of sexual assault against a former top Communist Party official has shined a spotlight on similar cases involving political dissidents, entertainers, business leaders and others who have run afoul of the authorities.
A look at those cases and the background on such actions.
WHAT HAPPENED TO PENG SHUAI?
Despite an outcry in the tennis world and global media, Chinese officials have not directly addressed the accusation posted online by Grand Slam doubles champion Peng more than two weeks ago. Peng said she was sexually assaulted by Zhang Gaoli, a former vice premier and member of the party's all-powerful Politburo Standing Committee.
Peng, 35, is a former No. 1-ranked player in women's doubles who won titles at Wimbledon in 2013 and the French Open in 2014. She also participated in three Olympics, making her disappearance all the more prominent with Beijing set to host the Winter Games starting Feb. 4.
Peng wrote in a lengthy social media post on Nov. 2 that Zhang had forced her to have sex three years ago, despite her repeated refusals. The post was quickly deleted from her verified account on Weibo, a leading Chinese social media platform, but screenshots of the explosive accusation quickly spread across China's internet.
WHY DO PEOPLE DISAPPEAR IN CHINA?
China says it is a nation "ruled by law", but the Communist Party ultimately holds sway and there are large grey areas of enforcement. Control over the press and social media allows authorities to keep word of disappearances quiet and to stonewall critics, although such news often gradually surfaces through underground and foreign sources.
Among Chinese celebrities in the entertainment world, tangling with the authorities can be a career killer. For business leaders, it can mean a loss of status, market access and possible incarceration. With political dissidents, it often means disappearance into the vast security state, without access to family or legal recourse.
Even before taking power in 1949, the Communist Party underwent numerous rounds of vicious internecine struggles during which those on the losing side were disposed of without due process. The 1966-76 Cultural Revolution saw politicians, educators and musicians locked up for years without charge, often in solitary confinement.
Today, the party's Central Commission for Discipline Inspection handles most major charges against ranking officials, who may drop out of sight for months before a terse statement is issued saying they are under investigation for "severe violations of rules and regulations". Heavy sentences are later announced, with little or no details given about the charges or the evidence brought against them.
WHAT FAMOUS PEOPLE HAVE GONE MISSING?
Notable people who have dropped from sight under circumstances that remain unclear include business leader Jack Ma and famous actress Fan Bingbing.
Ma, China's most prominent entrepreneur and the founder of Alibaba Group, the world's biggest e-commerce company, stopped appearing in public after he criticized regulators as being too conservative in an October 2020 speech.
Days later, the government ordered Ma's Ant Group, a financial service that grew out of Alibaba's online payments business, to suspend a planned stock market debut in Hong Kong and Shanghai.
Rumours on social media questioned whether Ma had been detained. Friends of Ma reportedly said he wasn't detained but decided to stay quiet following criticism of his comments. Ma reappeared two months later in a January 2020 video released by Alibaba but made no mention of his disappearance.
Fan disappeared for three months before news emerged that tax authorities had ordered her and companies she represented to pay taxes and penalties totaling $130 million.
People can drop off the map if they are linked to disputes with the politically well-connected involving business and reputation.
Businesswoman Duan Weihong disappeared in 2017 and her husband, Desmond Shum, said he didn't hear from her for four years until he was preparing to publish a book about corruption among Chinese elites. Shum told Time magazine his wife begged him in a phone call not to publish his book, "Red Roulette".
Duan, also known as Whitney Duan, was cited by The New York Times in a 2012 series of articles about the family wealth of then-Premier Wen Jiabao, China's No. 2 leader. It remains unclear what exactly prompted her disappearance.
A real estate mogul, Ren Zhiqiang, disappeared from public view in March 2020 after criticising President Xi Jinping's handling of the coronavirus pandemic. Ren was sentenced later that year to 18 years in prison on corruption charges.
WHAT OTHER KINDS OF PEOPLE DISAPPEAR?
In a rare case that appeared in the open, Swedish citizen Gui Minhai disappeared in 2015, when he was believed to have been abducted by Chinese agents from his seaside home in Thailand.
He and four others who worked for the same Hong Kong company that published books critical of the Communist Party all went missing at about the same time and turned up months later in police custody in mainland China.
A court in eastern China later sentenced him to 10 years in prison for "illegally providing intelligence overseas".
China has also snatched some foreigners.
Canadians Michael Kovrig and Michael Spavor were detained in China in December 2018, shortly after Canada arrested Meng Wanzhou, the chief financial officer of Chinese telecommunications giant Huawei, on a US extradition request. China delayed announcing their detentions for days, then denied that the arrests were linked. The two were released in September after Meng was allowed to return to China.
Even a scientist, gene-editing researcher He Jiankui, disappeared from public view for almost a year after announcing his controversial research at a conference in Hong Kong. He was eventually convicted of practicing medicine without a license in December 2019.
Accompanying the news of Peng's disappearance, the wife of the former president of Interpol, who was taken into custody on a trip back to China in September 2018, told The Associated Press that she and her lawyers have been unable to contact him since that date.
State media reported that Meng Hongwei admitted taking bribes, but Grace Meng said her husband was the victim of a political vendetta.
The disappeared also include large numbers of Uyghurs and members of other predominately Muslim minority groups who have been targeted in what the government calls a campaign against extremism, separatism and terrorism.
Following attacks on government and civilian targets, more than 1 million men and women were forced into prison-like political re-education camps officially described as de-radicalisation bases and job training centres.