Amnesty International said it was deeply disappointed by the South Korean Constitutional Court's decision to uphold the death penalty on Thursday.
In a five to four ruling, the Constitutional Court stated that capital punishment did not violate "human dignity and worth" protected in the Constitution.
"This is a major setback for South Korea and runs counter to the current abolitionist trend in the country, which has not executed in over a decade," said Roseann Rife, Asia-Pacific Deputy Programme Director at Amnesty International.
Amnesty International considers South Korea to be abolitionist in practice, as it has not carried out any executions since President Kim Dae-jung took office in February 1998. President Kim himself had previously been sentenced to death in 1980. However, death sentences are still handed down with currently 57 people remaining on death row.
Increasingly countries are moving away from using the death penalty as the ultimate punishment. More than 70 per cent of countries have a moratorium on executions or have abolished capital punishment.
"Despite this ruling, we call on the South Korean government to retain the country's abolitionist position and urge them to fully abolish this practice in the law. Any move backwards on this issue is extremely damaging to South Korea's international reputation. An economic leader, the country also should lead by example by fully respecting every individual's right to life," said Roseann Rife.
Amnesty International opposes the death penalty in all cases, as a violation of the right to life and the ultimate cruel, inhuman and degrading punishment. The death penalty is irrevocable, and there is always the risk that an innocent person will be executed.
Furthermore, the death penalty is inherently arbitrary and discriminates against those who are poor, marginalized or belong to minority communities.
The Constitutional Court of Korea was established in September 1988 and its functions include deciding on the constitutionality of laws, ruling on competence disputes between governmental entities, adjudicating constitutional complaints filed by individuals, giving final decisions on impeachments, and making judgments on dissolution of political parties.