North Korea released a South Korean employee detained for more than four months after Hyundai Chief Hyun Jung-eun’s four-day mission to the communist country.

Yoo Seong-jin, an employee for Hyundai Group, crossed the border and arrived at a South Korean immigration control center late Thursday, according to Seoul's Unification Ministry.

In a brief statement, Yu said he was happy to be back, and offered thanks to the South Korean government, his employer, and the South Korean people.

The 44-year-old technician worked at an industrial zone in the North's border city of Kaesong, where about 110 South Korean-run factories employ about 40,000 North Korean workers.

He was detained in March for allegedly denouncing the North's political system.

South Korean Unification Ministry Spokesman Chun Hae-sung says no payoffs were made.

He says South Korea has not given anything to the North in return for Yu's release.