A South Korean court has found billionaire Samsung heir Lee Jae-yong guilty of bribery, embezzlement, hiding assets overseas, concealing profit from criminal acts and perjury.

He has been sentenced to five years in prison.

Revelations of Lee's attempt to bribe South Korea's president to further his business ambitions fed public anger that led to the removal of Park Geun-hye as South Korea's leader.

The court said Lee, 49, hoped bribes for Park and her close friend Choi Soon-sil would secure government support for a merger of two Samsung units that strengthened Lee's control over the conglomerate.

Lee showed no reaction as the verdict was announced.

Al Jazeera's Step Vaessen, reporting from the court in Seoul, called the guilty verdict "unprecedented".

"It wasn't 12 years, as demanded by the prosecutors because although all charges were proven guilty, the amount of bribery that was paid - according to judges - was not the $38m that the prosecutors had said but less," she said.

"Nobody knows exactly how much right now, but it must have been in the millions of dollars."

Vaessen said judges considered important the fact the Lee paid briberies to Choi "to get something in reward".

A lawyer for Lee said he would appeal the "unacceptable verdict".

"We are confident that the ruling will be overturned," Sing Wu-cheoil said.

Under South Korean law, sentences of more than three years cannot be suspended. Lee's five-year sentence is one of the longest prison terms given to a South Korean business leader.

Park also has a trial under way, while Choi was sentenced to three years in prison in June.

"Apparently Park's trial will continue until October," said Vaessen. "With a five-year sentence against Lee, it's very much expected that it will be very difficult for her to be acquitted."

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Samsung, South Korea's largest business group, has acknowledged making contributions to two foundations as well as a consulting firm linked to Choi Soon-sil, a close confidante of the embattled South Korean leader who is also facing corruption charges.

At a December parliament hearing, Lee denied that the company paid bribes to pave the way for a merger in 2015.

Samsung made the biggest contributions of $16.8m to Choi's foundations.

Samsung is separately accused of funnelling millions of dollars to Choi to bankroll her daughter's equestrian training in Germany.

Prosecutors said the donations were made in exchange for government favours, allegations that Lee and Choi had denied.

Other former Samsung executives charged with Lee were also found guilty.

Choi Gee-sung, Lee's mentor, and Chang Choong-ki were sentenced to four years in prison. Two other former executives received suspended jail terms.