A popular actress suspected of abandoning her two children born through surrogate pregnancies has crossed an ethical line not only as an actress, but also as an ordinary citizen, a discipline organization of the television industry said on Friday.

"Acting skills are the basis of a career for actors and actresses, while ethics decide fundamentally whether the actors and actresses can be called human", the work ethics committee of China Television Artists Association said in an announcement released on its public WeChat account.

"Setting a good example by respecting society's ethics is a requirement in the television drama industry and is expected from the audience," the committee said.

"We call on all people working in the television drama industry to treat ethics as a lesson they should keep learning throughout their lifetime, to abide by laws and social ethics, and to set a good example for the public with their virtues and dramatic works," it added.

The announcement was made after Zheng Shuang, 30, an actress particularly popular among young people in China, was recently reported to have abandoned her two children, who were born in the United States through surrogate pregnancy.

On Monday, Zhang Heng, Zheng's ex-boyfriend, said in a microblog post on his Sina Weibo account that he had been slandered as a fraud who fled to the US.

Zhang said he was in the US, but was forced to stay there because he had to take care of two babies.

According to the birth certificates exposed by Zhang's friend on the internet, Zheng Shuang is the mother of the two babies. The boy was born in Colorado in December 2019 and the girl was born in Nevada in January last year.

In a recorded audio file posted on Monday by Sina Entertainment on Sina Weibo and is suspected to be a conversation among Zheng, her parents and Zhang's father, Zheng and her parents expressed their intention of abandoning the two children for others to adopt.

The incident has attracted wide attention, as surrogate pregnancy is strictly prohibited and strongly criticized in China.

The Regulations on the Assisted Reproductive Technology stipulate that trading gametes or embryos in any form is prohibited, and medical organizations and staff members are forbidden from applying for surrogate pregnancy in any form.

In a Weibo post on Tuesday, Zheng said the incident was a "very sad and private matter" for her, which she didn't want to talk about publicly.

She said her legal team had rejected the extortion from Zhang's side, who had threatened to expose her private affairs, adding that she had neither "violated the instructions" in China nor "all the laws and regulations" when she was abroad.