Beijing (CNN) A 9-year-old Chinese girl's mysterious weeklong disappearance came to a tragic end Sunday after authorities confirmed her lifeless body had been found in the East China Sea.

In a statement released Sunday, Zhejiang Provincial Police confirmed that missing girl Zhang Zixin had drowned in waters off Xiangshan county. They said that her body showed no signs of violence but ruled out her death as an accident.

Millions of people across China had been gripped by the case, closely following the developments as search crews had spent days trying to find the bespectacled second-grader with a long pony tail in waters and caves along the shoreline.

The girl's government services identity card was found in a pavilion near the coast last Wednesday night.

Zhang was last seen just over a week ago, when a witness saw her traveling with a middle-aged couple on a road not far from the search area around 8 p.m. on July 7.

The couple had been renting rooms at her family's house in rural Chun'an county, some 150 kilometers (90 miles) away, according to police.

A photograph provided by Xiangshan police of the missing 9-year-old girl Zhang Zixin.

When the two adults were seen again on surveillance cameras two hours later, the girl wasn't with them. Police said the man and woman, both hailing from the southern province of Guangdong, drowned themselves in a nearby lake later that night.

In their latest statement, police said the 43-year-old man, surnamed Liang, and the 45-year-old woman, surnamed Xie, had been swindling money from family and friends for years, and ran out of cash after traveling extensively across China.

Police said the couple had been increasingly discarding their personal belongings in recent months and an analysis of their social media posts pointed to a desire to commit suicide together with Zhang as their symbolic goddaughter.

In an interview with the mass-circulating Dushi Kuaibao newspaper Wednesday, a Zhejiang-based state-run publication, the girl's father Zhang Jun said the couple had tricked his elderly farmer parents, who were Zixin's primary caretakers, into letting them take the girl away while he was working in a northern Chinese city hundreds of miles away.

In the interview, Zhang Jun said the nightmare began when Liang and Xie told him on July 3 that they wanted to make Zixin a flower girl at a wedding in Shanghai. Despite his objections, Zhang said the couple took the girl with them the next morning.

For three days, Zhang Jun said he was able to stay in touch with Liang via WeChat, China's most popular social media platform. Liang promised to bring the girl home by the end of July 6 and sent frequent updates, according to the father, who said everything seemed "normal" initially.

In footage that Liang sent to Zhang Jun, who later shared with state-run media outlet Beijing News, Zixin can be seen visiting tourist sites with the two suspects and watching videos on a phone on a train. The girl appeared relaxed, answering Liang's questions with a smile. Her voice in audio messages also sounded relaxed.

But Zhang was worried that none of the locations were anywhere near Shanghai.

After being increasingly suspicious, Zhang Jun finally took an overnight train home on July 6. He said he spoke to Zixin for the last time midday on July 7, saying she sounded calm and told him she was in northern Xiangshan, a county just south of Shanghai.

By the time night fell on July 7, things had started to look more ominous. Liang had refused the father's offer to drive to their location to pick Zixin up, but agreed to have him pay for a taxi to drive them back to Zixin's home, according to Zhang Jun. Shortly afterward, Liang switched off his phone.

Zhang's family reported her missing to local police on Monday morning, and posted the girl's and Liang's information online the next day. After police confirmed the death of the two adults, Zixin's fate became a nationwide fixation.

Conspiracy theories abounded across Chinese cyberspace, with some commentators wondering aloud if Liang and Xie were members of a cult -- based on certain images and seemingly odd content posted by Liang.

Dismissing the speculation, Zhejiang police said Sunday that the two suspects didn't have criminal records and weren't found to have engaged in cult activities. Neither of them had used alcohol or drugs prior to killing themselves.

CNN has reached out to Zhang Jun for comment. His brother-in-law told the Beijing News on Sunday that the family would like to "have some quiet time" and would not field any interview requests for now.

"Although this result isn't the miracle we had hoped for, it's better than not finding the girl's body," he was quoted as saying.