The whereabouts of the Chinese woman who allegedly took classified information from South Korean diplomats through inappropriate relationships remained unclear Friday, as Seoul prepared to ask for Beijing’s official cooperation in investigating her.

Deng Xinming, the 33-year-old housewife at the center of the escalating sex scandal, has not been seen near her house or made contact with acquaintances since the news broke earlier this week.

Based on her recent relationship with a former Shanghai consul and his resignation from the government in January, the two are suspected to be hiding out together, sources said, citing Deng’s husband. The South Korean man, identified only by his last name Hur, arrived in Shanghai to reunite with Deng shortly after leaving the government, according to her husband.

Four officials, including former Consul General Kim Jung-ki, are currently under government investigation over allegations they leaked confidential state information to the Chinese woman while working in Shanghai.

Speculation has it that at least 10 more Korean officials had inappropriate relationships with Deng, who has disappeared from the public eye in an apparent bid to avoid investigators and the media.

The Seoul government said it will ask Beijing for official cooperation in investigating Deng, according to the Foreign Ministry here.

Seoul is to send a joint investigative team consisting of officials from three different ministries to verify rampant allegations which are so far unconfirmed. The team is scheduled to arrive in Shanghai Sunday.

“We have not received an answer from the Chinese government on whether it has opened a separate investigation into Deng,” a ministry official said on condition of anonymity.

Presiding over a policy meeting Friday, South Korean Prime Minister Kim Hwang-shik prompted officials to conduct proper investigations that will “reveal clearly what really happened.”

“Ministers and agency chiefs must pay special attention on setting up proper ethical standards of government officials,” he said. “The Foreign Ministry, in particular, should come up with measures to prevent indiscipline in overseas missions.”

The latest scandal was unveiled only months after the Foreign Ministry announced a set of reform measures to overcome a nepotism scandal that led to the resignation of its minister, highlighting the prevalence of ethical problems among senior public servants.

The four Korean officials, which include the former Justice Ministry official Hur, are suspected of having affairs with and passing classified government files to Deng, which were said to include contact information of some 200 high-ranking Korean officials and politicians as well as records related to their visa issuance.

As speculations grow here that Deng was an A-class spy hired by her government, reports said Friday that she was a rich woman with more than 10 billion won ($8.9 million) worth of property, including a luxury villa and restaurant.

The Chinese government has been expressing regrets about Seoul “turning the incident into a spy case.”

The Global Times, a newspaper affiliated with Beijing’s official People’s Daily, has warned of negative affects on Seoul-Beijing ties unless the case is “quietly dealt with.”

In a press briefing earlier this week, spokesperson of the Chinese Foreign Ministry said her government is “observing the incident with care,” without elaborating further.

By Shin Hae-in (hayney@heraldcorp.com)