Samsung’s heir-apparent Lee Jae-yong has been sentenced to five years in prison for corruption.
He was accused of bribery in a scandal that also saw the impeachment of South Korea’s former president, Park Geun-hye.
The case has gripped the public amid growing anger against South Korea’s biggest companies, known as chaebols.
Lee Jae-yong, who denied all charges, had faced a jail sentence of up to 12 years.
The 49-year-old, also known as Jay Y. Lee, the de facto head of Samsung, the world’s largest smartphone maker, had been detained since February on a string of corruption charges.
These included including bribery, embezzlement and hiding assets overseas.
Lee Jae-yong was accused of giving donations worth 41 billion won ($36 million) to non-profit foundations operated by Choi Soon-sil, a friend of South Korea’s former President Park Geun-hye, in return for political favors.
Prosecutors said the donations were made to Park Geun-hye’s confidante to win government support for a big restructuring of Samsung that would strengthen Lee Jae-yong’s control over Samsung Electronics.
A lawyer for Lee Jae-yonghas said already said they will appeal against the decision.
“We are confident the ruling will be overturned,” lawyer Song Wu-cheol told reporters after the ruling, according to Reuters.
Nevertheless this ruling represents a huge blow to South Korea’s biggest and most well-known business empire. Since the verdict, Samsung shares fell by 1%.
Lee Jae-yong’s conviction raises questions about his leadership of the conglomerate. He has been standing in as chairman since his father, Lee Kun-hee, suffered a heart attack in 2014.
The Samsung scandal contributed to President Park Geun-hye’s eventual impeachment. Park Geun-hye’s friend, Choi Soon-sil, has already been jailed for three years for corruption.