South Korean police have made apparent headway in the man-hunt for a fugitive businessman wanted over April's ferry disaster with the capture of his wife.
Kwon Yun-Ja, 72, was arrested on Saturday at a flat in the southern suburbs of Seoul following a successful ambush, Yonhap news agency said.
But her husband Yoo Byun-Eun, 73, was not at the site.
YTN TV showed Kwon, her face covered with a dark-brimmed hat, being taken into custody at the Incheon Prosecutor's Office.
Investigators want to question her to obtain information that may lead to the capture of her husband.
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Yoo is the patriarch of the family behind Chonghaejin Marine Co, which owned and operated the 6825-tonne Sewol ferry that sank on April 16 with the loss of around 300 lives, most of them schoolchildren.
He is wanted for questioning on possible charges of embezzlement and criminal negligence, as prosecutors investigate the extent to which the Sewol disaster was caused by a lack of safety standards and regulatory violations.
Yoo has no direct stake in Chonghaejin, but his children and close aides control it through a complex web of holding companies.
His wife Kwon was accused of diverting funds from one of Chonghaejin's subsidiaries where she serves as the CEO.
A reward of 500 million won ($A530,160) has been offered for information leading to the capture of Yoo and 100 million won for that of his eldest son, Yoo Dae-Kyun.
Last week, thousands of police twice raided the compound of a splinter religious group in pursuit of Yoo but to no avail. Yoo is reportedly the de-facto leader of the church.
Several church followers suspected of helping Yoo evade a nationwide dragnet have also been arrested after he defied an official summons to surrender to prosecutors.
