The fugitive former head of South Korea's collapsed Daewoo Group has handed himself over to prosecutors.
Kim Woo-Choong said he felt "deeply sorry"
Kim Woo-Choong, 69, landed near Seoul on an early morning flight from Vietnam and was immediately arrested by police.
He fled abroad six years ago after his business empire, once a symbol of the country's economic success, crashed with debts of more than $70bn (£38bn).
Seven other former Daewoo executives have been found guilty of fraud. Mr Kim is facing similar charges.
"I lower my head deeply down and apologise for having caused troubles to people over the Daewoo Group problem," he said in a written statement issued upon his arrival at Incheon International Airport from Hanoi.
"I will take whatever responsibility I am supposed to take over the Daewoo Group incident. I feel deeply sorry," he told reporters as he was taken away under police escort.
Mr Kim's whereabouts have been a mystery, though there have been reports of him living in Vietnam and Europe.
He was once revered by Koreans as a symbol of their country's rapid economic growth, says the BBC's Charles Scanlon in Seoul.
He bought a small textile company in the late 1960s, and three decades later had built South Korea's second largest industrial conglomerate.
It made cars, ships and electronics products, and had factories around the world.
But the group came crashing down six years ago in the aftermath of the Asian financial crisis.
Mr Kim is alleged to have resorted to massive accounting fraud to try to prop up his ailing empire.
Our correspondent says his return is seen as a test of the government's commitment to clean up notoriously lax corporate governance.
In the past, he says, it has given lenient treatment to businessmen convicted of fraud.