BEIJING – Yu Qiyi had a promising career in a government investment company when he disappeared on his way home from a business trip March 1. Thirty-eight days later, the bespectacled, boyish-looking engineer died after turning up in a hospital emaciated, with bruises on his arms and thighs, dark welts on his buttocks and scrapes on his feet and shins.
In between, Yu was held by investigators from China's ruling Communist Party in secret detention frequently used but not regulated by law. Since his death last week, he's become a rallying point for reformers who want to do away with a system that is prone to abuse but that Chinese leaders depend on to keep members in line.
Photos of Yu's body have ricocheted around the Internet, prompting thousands of comments from ordinary Chinese citizens on popular Twitter-like microblogs, as well as from journalist in the state media.
"If power is not locked in the cage of institutions, everyone will find it hard to feel secure. From ordinary citizens to leading cadres, everyone could become a victim," reporter Chen Yuming of the official Xinhua News Agency posted on the agency's account last week.
Yu's family says the injuries are proof that he was beaten, starved and otherwise tortured by investigators in the eastern city of Wenzhou where he lived.
"He was thin like a beggar," said Wu Qian, his ex-wife with whom he still lived, describing seeing Yu on April 9 in a local hospital. "He was lying there so pitifully. ... Anywhere that we could see, there were injuries on his body."
Wu said in an interview that the hospital's medical records cited drowning as a potential cause of death. A terse official statement carried by state media said Yu had an unspecified accident while being held by the party's local inspectors and that he died in the hospital after rescue attempts failed. It said an investigation was underway.
Wenzhou police referred calls to the office of local party investigators, where phones rang unanswered this week. Lines were constantly busy at the city's propaganda office. The hospital where Yu was sent declined comment.
Yu's case is drawing attention to a feared tool of communist rule: the detention of party members by internal investigators.
Those being investigated are ordered to appear at a designated time and a designated place for questioning, yielding the euphemism by which these investigations are widely known: "shuanggui," a term that roughly translates to "dual designation."
In practice, it's a system in which suspects are whisked away into a shadowy detention. It operates beyond the law, with people held for weeks and months at a time with no regard for the normal, if often ignored, legal protections Chinese citizens are supposed to be entitled to.
The state-run Global Times newspaper said targets of investigations are "asked to confess to wrongdoings."
"Shuanggui faces no constraints and that makes it easier for torture to be used to obtain confessions," said Shen Liangqing, a former prosecutor who has become a government critic and has investigated the detention system.
Interrogators say: "'We will beat you to death, take your corpse down the mountain and say you committed suicide by jumping,'" Shen said. "That's how they threaten them."
Defenders of the system say party investigators need unchecked power to prevent officials suspected of malfeasance from using their influence to block such inquiries. By keeping them in solitary confinement, the argument goes, officials are unable contact others who might be implicated or police or judges they might have influence over.
And it has been used against powerful officials, most recently Bo Xilai, a high-ranking politician brought down in spectacular style last year following his wife's involvement in the murder of a British businessman. The former railways minister, Liu Zhijun, who now faces charges of taking bribes and abusing his power, also was under the party's investigative detention system.
Yu was wanted for questioning for possible corruption in a land deal when he was picked up by investigators.
Run by the party's Discipline Inspection Commission, the investigations have time limits of up to six months and usually take place in hotels or guesthouses, according to a 2010 book on arbitrary detention in China by legal scholar Flora Sapio.
Detainees are guarded even when they use the toilet, Sapio writes, and are subject to sleep deprivation and beatings.
Because the targets and interrogators are party members and are bound by the party's disciplinary code, the process is girded in silence, its details mostly kept out of public view. When the probe is concluded, investigators sometimes turn the suspect along with selected evidence to prosecutors for what is often a perfunctory prosecution with guilt a foregone conclusion.
No figures are made public on the number of people put through the party's detention system annually. Shen said the number of corruption cases the party investigates — about 150,000 cases last year — provides some indication, though the detentions are likely to be far higher since each case usually involves multiple suspects.
The attention that Yu's case has brought comes at an inconvenient time for the party. There is growing pressure from legal reformers and the public to do away with another form of punishment with flimsy legal underpinnings: a system that allows police to jail people in labor camps for up to four years without a court trial or judicial review.
Because recently installed President Xi Jinping came to power pledging to root out widespread corruption, the shuanggui detentions may be used even more frequently, not less — setting back legal reforms.
"The use of shuanggui delivers not justice, but selective and vindictive prosecutions often based on torture, and will do little to straighten out China's rotten officialdom," Human Rights Watch researcher Maya Wang said.
Before he died, Yu, a party member since 1998, had been a rising figure in the Wenzhou Industry Investment Group, a state-owned company that according to its website invests in energy and other industries and manages 4.6 billion yuan ($750 million) in assets. Yu had been appointed by provincial leaders for a temporary assignment at the Cabinet agency in Beijing that oversees China's biggest state-owned companies.
He was arriving back from the capital on March 1 but instead of being picked up as usual by his ex-wife, Wu, who was waiting in the car outside, he made a hurried phone call before being whisked away by investigators. It was the last time she heard his voice.
In the days that followed, Wu learned from one of Yu's colleagues that Yu was being investigated by the Discipline Inspection Commission — though she was never formally notified. Through other sources, she learned Yu was suspected of wrongdoing because he served as a middleman in a land deal that eventually fell through.
The same colleague called Wu in the early hours of April 9 telling her that Yu was in the hospital severely ill and doctors were trying to save him. Wu rushed there to find him unconscious and battered, with blood coming out of his ears and nose.
"How did you become like this?" Wu asked, shaking the unconscious man as she pleaded with a doctor: "You must save him. What happened to him?"
The family has consulted friends in the police and they believe the bruises paint a picture of the torture inflicted on him: The discoloration and abnormal swelling of his feet are consistent with that of someone made to stand for long periods on blocks of ice; the bruises on his ribcage and back and severe bleeding point to beatings that likely caused internal organ damage; his dramatic weight loss a sign that he was deprived of food.
The family has hired two prominent rights lawyers to push authorities to fully investigate the case. They want the investigation taken away from the city prosecutor's office and moved to a higher level agency.
Yu's ex-wife said she hoped that his death would not be in vain.
"I want to restore the truth and find justice for him," she said. "I hope he might be able to stir debate about the current system. ... Because for everyone else, they might suffer the same fate as him some day."
Follow Gillian Wong on Twitter at twitter.com/gillianwong
Associated Press researcher Flora Ji contributed to this report.