The decision is another blow to Samsung as it struggles with falling profitability and a trade spat with Japan.
South Korea's top court on Thursday ordered a lower court to review part of a bribery case against Samsung heir Lee Jae-yong, who received a suspended sentence in connection with an influence scandal that brought down former president Park Geun-hye.
The decision could deal a blow to the world's biggest smartphone and memory chip maker if its de facto head is imprisoned. It comes at a time Samsung profits have slumped and South Korea and Japan are in a dispute that has restricted trade between the two Asian powerhouses.
The Supreme Court said a lower court failed to correctly evaluate what constitutes a bribe and that it should reconsider Lee's suspended sentence.
Chief Justice Kim Myeong-su said that three horses worth around $2.8 million (€2.5 million) that Samsung donated to the daughter of Park's friend Choi Soon-sil for equestrian training should be considered a bribe designed to influence the ex-president.
Lee, vice-chairman of Samsung Electronics, was sentenced to five years in prison for bribing Choi in order to seek favors from the now-imprisoned former president.
Last April, Park was convicted of receiving or demanding more than $20 million from conglomerates, sharing secret state documents, blacklisting artists critical of her policies, and firing officials who resisted her abuses of power. She is serving a 25-year prison sentence.
Lee was released from prison after a year, and an appeals court later suspended his sentence to two-and-a-half years.
cw/ng (AFP, Reuters)