The latest is a 26-year-old named Ji Yingnan, who says she discovered at the end of last year that her fiance, a powerful Communist Party official in Beijing, had been married with a teenage son the entire time they were together.

In recent weeks, Ji has released hundreds of photos online that offer a rare window into the life of a Chinese central government official who — despite his modest salary — was apparently able to lavish his mistress with luxury cars, go on shopping sprees at Prada and tuck more than $1,000 in cash into Ji’s purse every day when they first met.

“I never imagined that the one I loved so much, the one I gave so much love to, the one who lived four years with me, would become my enemy one day,” said Ji on a recent evening at a KFC near her apartment, where she says she stays holed up for days at a time.

Ji put her head in her hands. “It is terrifying to experience this kind of relationship,” she said.

After years in which Communist Party officials were considered untouchable, evidence of their foibles now regularly spills onto the Internet. Government censors often try to stamp out the news, but officials plagued by sex scandals — usually at lower levels of the party — are also being pushed out as the country’s new leaders try to prove they’re serious about punishing misconduct.

A powerful energy official, Liu Tienan, lost his job in May after his former mistress told a journalist that Liu had defrauded banks out of $200 million. Last year, a sex video showing a Chongqing district party chief with a woman who was not his wife was leaked online, forcing the official, Lei Zhengfu, to step down.

Ji identified her former lover as Fan Yue, a deputy director at the State Administration of Archives. He is now under investigation, according to a staffer there who spoke on the condition of anonymity. “We don’t have further information to release,” the staffer said. “We will make an announcement when there is a resolution.”

Fan could not be reached to comment. His cellphone number appears to have been disconnected.

A well-known Chinese blogger who has posted Ji’s photos and videos on his Web site said he spoke with Fan last month. Fan told the blogger that he didn’t spend as much money as Ji claims, saying it was less than $1.7 million but more than $500,000. “This woman is not good. She is too greedy,” the blogger, Zhu Ruifeng, said Fan told him. “I couldn’t handle her. So I had to leave her.”

Political scandals centered on mistresses — who are known as “xiao san,” or “little third,” in Chinese slang — have become so common that the party’s official daily newspaper ran an editorial in May saying the country cannot rely on spurned lovers alone to expose its corruption problems.

“Some people have said that the anti-corruption departments at all levels perform worse than the mistresses,” said the editorial in the People’s Daily. “Although it’s a joke, it reflects a serious question: Whom should the anti-corruption effort depend on?”

The question has taken on a new urgency as Xi, who took power in March, has vowed to root out crooked officials both powerful and lowly, or as he put it, “tigers” and “flies.”

“Every country has sex scandals. Just look at the United States and Bill Clinton,” said Deng Xiaogang, a sociology professor at the University of Massachusetts in Boston. “But this is different because of China’s political environment. [The officials] are using public money.”

Blue fur and pearls

Ji has perhaps gone further than any of the spurned mistresses.

She has made dozens of CDs containing photos and videos of her relationship, handing them out at the front gates of Zhongnanhai, central headquarters of the Chinese Communist Party.

The photos, now plastered all over the Internet in China, look like ordinary mementos from a happy relationship. But they also capture the extravagant lifestyle of the ruling elite in a country with rampant income inequality.

For example: Shopping sprees with Ji posing in blue fur and pearls as Fan shows off a receipt for their big purchases. A birthday celebration where he proposed marriage to Ji, who is wearing a gold crown and sequined dress. The couple standing on the bow of a ship with arms outstretched, re-creating the scene from the movie “Titanic.”

Ji said the two met at a restaurant on Ji’s birthday in June 2009, when she turned 22 and Fan was 37. He wasn’t like the men her age, she said. He had manners. When they talked, they seemed to share the same values. Fan told her that he worked in information technology, she said.

From the start, it was obvious he had money. The first time they went shopping, Ji said, the couple went to Prada and paid $10,000 for a skirt, a purse and a scarf. A month after they met, Fan rented an apartment for them that cost $1,500 a month and spent more than $16,000 on bedsheets, home appliances, an Apple desktop and a laptop, according to Ji. Then he bought her a silver Audi A5, priced in the United States at about $40,000, she said.

There were trips to beach resorts in Hainan, a beautiful island off the southern coast of China. On another trip to Prada, Fan spent more than $33,000 on his fiancee and her sister, according to Ji.

“He put cash into my purse every day,” said Ji in a letter to the Communist Party complaining about Fan’s behavior. It was for “daily use, buying clothes and going out for fun.”

Ji said she spent her days cleaning their home, folding her boyfriend’s socks and waiting for him to come home. He was home with her at least five or six nights a week, Ji said. When he didn’t come back at night, he said he was working late and needed to sleep in the office, she said.

A year after they met, Ji found Fan’s work ID card while sorting his clothes. That’s when, she says, she learned that he worked for the central government.

“I didn’t know exactly what his job was,” Ji said. “He told me his position was confidential.”

The source of the money was clear, though: three businessmen who spent time with Ji and Fan and who would sometimes directly route money to Ji’s bank account, she said. It was not clear what the men may have hoped to gain from Fan; Ji said he didn’t discuss work matters with her.

The businessmen, whom Ji identified as Jin Zhong, Chen Guiyang and Ye Zhenbo, could not be reached to comment, although Ji has records of text messages from one of the men since the scandal broke, demanding that she return all the money that was spent.

End of a fairy tale

After the couple had been engaged for more than a year, Ji began pressing her fiance on why they weren’t planning a wedding, she said. In China, it’s traditional for couples to purchase real estate before getting married. Fan resisted buying a home for them, she said.

Finally, at the end of last year, he confessed to having a family, Ji said.

“I felt I was a princess living in a fairy tale. But now, I don’t believe anyone,” said Ji, wearing a simple white top, cropped jeans and a pair of pink and white Crocs. (She says she no longer wants to wear the luxury clothes the couple bought together.)

“Fan Yue’s case is very unique,” said Zhu, the blogger. “Everyone knows the corrupted officials have mistresses, but few of the mistresses will pop up in front of the public.”

Ji, who spoke with fierce determination, said all she wants is for Fan to apologize to her in person — and for her experience to cause the government to crack down harder on corruption.

“People’s awareness is becoming stronger,” she added. “People won’t believe what they’re told as easily. In the era of the Internet, the government cannot hide things from people.”

**Zhang Jie contributed to this report.