(Bloomberg) -- Health authorities in the southern Chinese coastal city of Xiamen plan to probe an assisted reproduction clinic after local media exposed a secretive surrogacy service that’s reportedly helping deliver more than 300 babies a year.

Undercover reporters at Shanghai-based The Paper visited clinics in Hangzhou and Xiamen controlled by Longduhua Medical Group (Hong Kong) Ltd., which provides surrogacy, a practice that’s illegal under Chinese law.

The Paper contacted the local branches of China’s top health regulator — the National Health Commission — before running the video and story Monday. Health authorities in Hangzhou and Xiamen vowed to investigate.

Despite Beijing’s repeated crackdowns and an outright ban, underground surrogacy services continue to thrive in China, fueled by couples either wishing to skirt the country’s decades-long (but now defunct) one-child policy or those unable to conceive or carry a fetus on their own. There are signs attitudes are starting to change, with lawmakers recently debating the need for surrogacy amid China’s declining birth rate.

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Underground surrogacy clinics have been emboldened by the fact that Beijing didn’t clearly spell out the legal consequences for those flouting the ban. When The Paper’s undercover reporters asked what would happen if they were caught doing the surrogacy, representatives said only the doctors would get their medical licenses revoked and the medical institutions might be fined.

With packages starting at 550,000 yuan ($77,000), Longduhua’s clinics evaluate clients’ fitness for procedures such as egg retrieval and in-vitro fertilization. Then the clinics find a surrogate mother in China, no older than 32, to insert the embryo and let them carry it to full term.

Additional charges can bring the cost to more than 1 million yuan and the clinics guarantee success in services such as fertilization, creating twins and renewed surrogacy after miscarriage, according to The Paper’s report.

Longduhua was founded by Liu Baojun, according to The Paper’s report. Other local media reported in 2018 that Liu helped an elderly couple in eastern China transfer four embryos from their son and his wife — both of whom died in a car crash in 2013 — to a fertility clinic in Laos, where a local woman carried and successfully delivered a baby in 2017.

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Should Longduhua babies be found to have deformities after birth, clients can start a new surrogacy or claim a refund. A representative from one clinic was filmed as saying the company would “take care of the deformed child.”

Mothers are also guaranteed a legitimate birth certificate, documentation that’s crucial for enabling access to healthcare, education and other government-backed services later in a baby’s life.

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Liu also appears to be an embodiment of the success of his own practice. Longduhua’s office in Xiamen has a giant poster showing three babies, which representatives said are Liu’s own, delivered by two surrogate mothers, and two of which are twins.

©2023 Bloomberg L.P.