Samsung leader Lee Jae-yong was released from prison on parole a year early on Friday.

He was convicted of crimes related to the explosive corruption scandal that toppled South Korea's previous president Park Geun-hye, who has been in jail since 2017 and won't be released until 2039 if she fully serves her term.

Lee served a total of 18 months for embezzling millions of dollars from corporate funds to ensure government support for a 2015 merger between two Samsung affiliates that tightened his control over the corporate empire.

His case triggered nationwide protests and led to the impeachment and imprisonment of Park.

The Samsung leader apologised to the people of South Korea for being released on parole earlier, saying he had "caused too much concern to the people".

"I'm listening carefully to your worries, criticisms, concerns, and high expectations about me. I will do my best," he added.

He is the latest in a long line of South Korean corporate bosses receiving lenient punishment for corruption and financial crimes.

His release has divided people with hundreds of demonstrators standing behind police lines simultaneously shouting slogans denouncing or welcoming his early comeback.

Lee still has to face the Seoul Central District Court on Thursday for another trial over alleged stock price manipulation, auditing violations and other financial crimes related to the 2015 merger.

His lawyers insisted the allegations in that case were not criminal acts but were normal business activities.

Current President Moon Jae-in, who won the presidential by-election in 2017, pledged to curb the excesses of "chaebol", South Korea's family-owned conglomerates, and end their cozy ties with the government.

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