The main suspect in a Gangnam murder case had previously been involved in a criminal case with the victim involving cryptocurrency, according to legal professionals and reports released Monday.

The suspect, a 35-year-old only identified by his surname Lee, had reportedly been investigated by police for trying to seize a third party’s cryptocurrency assets in February 2021. Lee was sent to the prosecution on charges of extortion, while the third party was dismissed for a minor misdemeanor offense. The third party in question turned out to be the murder victim.

Police suspect cryptocurrency theft as the main motive for the killing.

Apart from Lee, the two other suspects -- a 30-year-old surnamed Yeon and a 35-year-old surnamed Hwang -- had no known connection with the victim, according to police.

The three suspects were apprehended by police Thursday on charges of kidnapping and murder after allegedly abducting a woman in her 40s near her residence in Yeoksam-dong, Gangnam-gu, at around 11 p.m. Wednesday, before killing her and disposing of her body near Daecheong Dam in Daejeon.

Police issued emergency arrest warrants for the suspects on Saturday after one confessed to committing the crime to obtain cryptocurrency assets belonging to the victim, thought to be worth billions of won (approximately millions of dollars).

According to reports, the victim and her husband, who is reportedly in prison, run cryptocurrency-related companies.

Police added that they would investigate further to see if there were accomplices in the alleged murder, as other investors who suffered losses had also stolen cryptocurrency assets from the third party.

Apart from those related to cryptocurrency, a man in his 20s was arrested with a preliminary charge of murder for helping the suspects plan the killing.

On Monday, the Seoul Central District Court granted the prosecution’s request to issue formal arrest warrants for the three suspects. Lee reportedly denied all allegations of abduction and murder, but testified that he had lost money after investing in the victim’s company.