The Cultural Heritage Administration sent an official letter on Wednesday to the current possessor of a historical book titled “Hunminjeongeum Haeryebon Sangjubon,” strongly demanding its return to the state, a CHA official confirmed to The Korea Herald on Friday.

The historical book, although yet to be officially designated, is considered equivalent to a national treasure-level cultural heritage. Another Haerye edition of the book, found in 1940 inside an old house in Andong, North Gyeongsang Province, was designated as a National Treasure in 1962.

In 2008, the book’s owner, 60-year-old Bae Ik-gi, said that he stumbled upon the “Hunminjeongeum Haeryebon Sangjubon” while tidying up his home in Sangju, North Gyeongsang Province. Until then, only one "Hunminjeongeum Haeryebon” -- the one found in 1940 -- was believed to exist under the auspices of the Kansong Art Museum in Seoul.

“Hunminjeongeum Haeryebon” contains valuable explanations and examples of the principles behind the creation of Hunminjeongeum, an early form of the Korean language that King Sejong created in 1446 with an aim to enhance the country’s literacy.

The term "Sangjubon" was coined using the city name Sangju, with the suffix "bon," a word which refers to a book or a copy.

Following Bae's discovery, Cho Young-hun, an antique dealer in Sangju, claimed ownership of the book. Cho accused Bae of stealing “Hunminjeongeum Haeryebon Sangjubon" in 2008, but Bae was acquitted due to lack of evidence to prove the theft, according to reports.

Cho then filed a lawsuit against Bae to return the book in 2010. The Supreme Court ruled in favor of Cho’s ownership.

Despite the court ruling, Bae kept refusing to return the book. This reportedly prompted Cho's decision to donate the book to the CHA.

In May 2012, Cho transferred the ownership of “Hunminjeongeum Haeryebon Sangjubon” to the CHA at a ceremony held at the National Palace Museum of Korea, in which the ancient book officially became government property.

Since then, the CHA has urged Bae to return the book, but Bae has refused to do so. In 2012, the CHA retroactively classified “Hunminjeongeum Haeryebon Sangjubon” as a stolen cultural heritage from 2008.

The CHA's 2012 announcement on the stolen heritage classification, available at the office's official website, reads, "'Hunminjeongeum Haeryebon Sangjubon' is equivalent to National Treasure No. 70 'Hunminjeongeum Haeryebon Sangjubon' (at the Kansong Museum) … ‘Hunminjeongeum Haeryebon Sangjubon' seems to be in better condition than the current national treasure, despite its loss of four pages of the preface and one page of the latter part."

A CHA official explained that the "Hunminjeongeum Haeryebon Sangjubon" discovered in 2008 features annotations that one of its owners apparently added during the Joseon era (1392-1910), giving a deeper understanding of the document's historical background.

In 2015, a fire broke out at Bae’s residence, an accident that cast uncertainty on the condition of “Hunminjeongeum Haeryebon Sangjubon.”

Since then, Bae has refused to disclose information on the book's condition. During an interview with local media in 2019, he commented that disclosing its whereabouts and its present state is difficult due to "personal reasons."

Police and prosecutors raided Bae's office and residence in 2011 and 2022, but could not find the book.

In 2015, Bae revealed his intention to sell the book for some 100 billion won ($75 million) during an interview with Hankyoreh, a local media outlet. However, the book's return did not take place due to budget disputes and doubts about its preservation, according to the Hankyoreh report.

"We are exploring different options, including potential legal action, while simultaneously urging Bae to return the ‘Hunminjeongeum Haeryebon Sangjubon’ voluntarily," a CHA official said.

This is the 18th time since 2017 that the CHA has sent letters requesting for the book's return to Bae. The due date requested for its voluntary return is Nov. 20.