SEOUL - For the past two years, the eldest daughter of South Korea's richest man has been mired in divorce proceedings.

Samsung heiress and Shilla hotel head Lee Boo Jin, 46, divorced Mr Im Woo Jae, a consultant at Samsung Electro-Mechanics, in January this year.

It was the end of the "Cinderella" marriage of one of the richest heiresses in South Korea to a rank-and-file employee.

She was granted custody of their seven-year-old son, and Mr Im is allowed to visit their son once a month.

The division of assets was not discussed at the time, The Korea Herald reported.

He is now claiming 1.2 trillion won (S$1.4 billion) from her, a sum believed to be the largest divorce settlement ever sought in the country, reports say.

In court papers filed last month, he is also seeking damages of 10 million won ($11,700) for "mental anguish".

It is understood that his claim is unlikely to succeed, as her assets were accumulated before their marriage in August 1999.

Reports said that 99 per cent of Ms Lee's assets are shares in various Samsung companies. Forbes estimates her net worth to be US$1.64 billion as of July 9, 2016.

However, the aggressive claims could form the basis of negotiations for a settlement.

In 1999, their marriage against the wishes of their parents was the talk of the town. He was said to be an employee of Samsung whom she had met during volunteer activities for Samsung Foundation.

Recently, Mr Im revealed that it was a cover story and he was actually Ms Lee's bodyguard. He also claimed that after marrying Ms Lee, her father, Samsung chief Lee Kun Hee, sent him to graduate school in the United States although he did not speak English.

He was under so much pressure he attempted suicide twice, Mr Im said. After he returned, he joined Samsung and rose to become the vice-president of Samsung Electro-Mechanics.

Ms Lee filed for divorce in 2014, but they were said to have been living apart since 2012.

He is the only member of the family who was not the scion of a South Korean family conglomerate, or chaebol.

Mr Lee Kun Hee has one son and two daughters. His son, Lee Jae Yong , 48, parted ways with his wife, Lim Se Ryeong, in 2009. She is the daughter of the Daesang Group's honorary chairman Lim Chang Wook.

Second daughter Lee Seo Hyun, 42, is married to Mr Kim Jae Youl, the son of Korean newspaper Dong-A Ilbo's former president.

His third and youngest daughter, Lee Yoon Hyung, committed suicide in New York City in 2005.