Billionaire Samsung heir Lee Jae-yong has been sent back to prison after a South Korean court sentenced him to two-and-a-half years over his involvement in a 2016 corruption scandal that spurred massive street protests and ousted South Korea's then-president.

In a retrial, the Seoul High Court found Lee guilty of bribing then-president Park Geun-hye and her close confidante to win government support for a 2015 merger between two Samsung affiliates that helped strengthen his control over the country's largest business group.

Lee's lawyers had portrayed him as a victim of presidential power abuse and described the 2015 deal as part of "normal business activity".

Wearing a mask and black suit and tie, Lee was taken into custody following the ruling. He did not answer questions by reporters upon his arrival at the court.

Injae Lee, a lawyer who leads Lee Jae-yong's defence team, expressed regret over the court's decision, saying that the "essence of the case is that a former president abused power to infringe upon the freedom and property rights of a private company".

He did not specifically say whether there would be an appeal. Samsung did not issue a statement over the ruling.

Lee Jae-yong helms the Samsung group in his capacity as vice chairman of Samsung Electronics, one of the world's largest makers of computer chips and smartphones.

In September last year, prosecutors separately indicted Lee on charges of stock price manipulation, breach of trust and auditing violations related to the 2015 merger.

It was not immediately clear what his prison term would mean for Samsung.

Samsung is coming off a robust business year, with its dual strength in parts and finished products enabling it to benefit from the coronavirus pandemic and the prolonged trade war between the United States and China.

Samsung's semiconductor business rebounded sharply after a sluggish 2019, driven by robust demand for PCs and servers as virus outbreaks forced millions of people to stay and work at home.

The Trump administration's sanctions against China's Huawei Technologies have meanwhile hindered one of Samsung's biggest rivals in smartphones, smartphone chips and telecommunications equipment.

Lee, 52, was originally sentenced in 2017 to five years in prison for offering 8.6 billion won (£5.75m) in bribes to Park and her longtime friend Choi Soon-sil.

But he was freed after 11 months in February 2018 after the Seoul High Court reduced his term to two-and-a-half years and suspended his sentence, overturning key convictions and reducing the amount of his bribes.

The Supreme Court last week confirmed a 20-year prison sentence for Park, who was convicted of colluding with Choi to take millions of dollars in bribes and extortion money from some of the country's largest business groups, including Samsung, while she was in office from 2013 to 2016.

The ruling meant that Park, who also has a separate conviction for illegally meddling in her party's candidate nominations ahead of 2016 parliamentary elections, could potentially serve 22 years behind bars until 2039, when she would be 87.

Choi is serving an 18-year prison sentence.

In a news conference on Monday, South Korean President Moon Jae-in said he has no immediate plans to grant presidential pardons to Park and another imprisoned former president, Lee Myung-bak, who is serving a 17-year term for corruption.