A surrogate mother, an infertile couple and a broker, have been sent to prosecution for indictment over an illegal surrogacy arrangement involving a payment of 50 million won ($37,890) from 13 years ago.

The Gwangju Bukbu Police said Thursday that the surrogate mother, who is in her 30s, the couple in their 50s, and the surrogacy broker were referred to the prosecution without detention. The four are accused of violating South Korea’s Child Welfare Act.

According to police, the surrogate mother became pregnant after undergoing intrauterine insemination, using the husband’s sperm at an obstetrics and gynecology clinic in Daegu in 2010. She gave birth to a baby boy in April 2011 at a hospital in Seoul and handed the child over to the couple in exchange for a payment of 50 million won ($37,890).

The couple is reported to have connected with the surrogate through a broker via an online forum for couples struggling with infertility.

Any form of surrogacy, an arrangement in which a third-party woman bears and delivers a child for another couple or individual, is illegal in South Korea.

As children born through surrogacy are legally considered the offspring of the birth mother here, paying a surrogate to transfer a child may be viewed as child trafficking under the law. Under the Child Welfare Act, individuals who transfer or receive a child in exchange for monetary gain can face up to five years in prison or a fine of up to 30 million won.

The surrogacy issue also falls under the Bioethics and Safety Act, which prohibits the provision or use of an embryo, egg or sperm in exchange for monetary benefits or any other form of compensation, as well as enticing or brokering such acts. Violators of this law can face imprisonment for up to three years.

Authorities uncovered the case, which had gone unnoticed for 13 years, during a nationwide investigation into undocumented births. When a child is born in a hospital, a temporary newborn registration number is typically issued. However, the couple registered the birth at the administrative office and claimed that the baby was born at home.

The Gwangju Buk-gu District Office became suspicious upon noticing a temporary registration number but no corresponding child report to the administrative office. The district then reported the case to the police for investigation.

The police then identified the woman, a resident of Gwangju, as the surrogate mother. After interrogating, they uncovered evidence and subsequently identified the broker as well as the couple who had been raising the child.