Police said Thursday they have been able to verify the identity of a Chinese woman found dead on South Korea's resort island of Jeju last week thanks to a fingerprint of her left index finger.

Investigators at the Seogwipo Police Station said the fingerprint, about 1 centimeter and invisible to the naked eye, was lifted from the badly decomposed body of the woman, whose name has been withheld.

The body of the dead woman, 22, was discovered by a man gathering bracken near a barley field in the city of Seogwipo on South Korea's largest island of Jeju on April 13. It was partially covered by grass and soil, and badly decomposed.

The woman, who entered South Korea as a tourist on Oct. 7, 2015, and overstayed the visa-free period to work, left the same fingerprint as the one collected on her immigration records.

The police combed the area near the barley field on April 13-14 for any possible belongings but found nothing.

A ray of hope was given the next day, when a coroner extracted the fingerprint, which was left intact about four months after her death, in an autopsy. It prompted police to scurry to the immigration office to do a cross-comparison of her fingerprint with those of foreigners who arrived on the island.

On Friday night, the police successfully determined her identity with the help of the immigration office and found out she is a Han Chinese from the southern part of the country.

Earlier this week, the police arrested a South Korean male suspect in connection with the murder but released him because of a lack of evidence.

The suspect was a regular customer at a bar where she was working before she went missing around the end of last year.

The Chinese woman was confirmed to have arrived on the South Korean island in October last year by taking advantage of the country's visa-free entry for Chinese tourists that allows foreign tourists aboard cruise ships to enter South Korea and stay here for 30 days without a visa.

She is believed to have been dead for less than four months, because the owner of the barley field did not see the body when he planted barley seeds in December and January. (Yonhap)