Despite the appeals by human rights activists to the Government of Singapore to commute his sentence, Abdul Kahar was hanged as scheduled at Changi Prison, and he was 68 years old at the time of his execution.

His father, who served in the British army, died at age 40 during Abdul Kahar's childhood years, leaving his mother as the sole breadwinner and caregiver of her children.

As the total amount of drugs exceeded the legal minimum of 15g, Abdul Kahar would face the mandatory death penalty if found guilty under the laws of Singapore.

However, there were evidence which proven that Abdul Kahar had knowledge of the drugs and there were also a total sum of over $100,000 in cash found in his home, indicating these to be the criminal proceeds he received from trafficking diamorphine.

[9] Two months later, the High Court judge Choo Han Teck ruled in a follow-up judgement that Abdul Kahar was indeed a courier and gave him the benefit of the doubt, which would spare him from a death sentence.

On 16 August 2018, while he still remained on death row at Changi Prison, Abdul Kahar filed for an application to reopen his case through his lawyer Rupert Seah.

Seah, in the application, argued against the constitutionality of the alternative sentencing regime in the Misuse of Drugs Act, stating that it violates the principles of equality before the law and separation of powers.

This was done during the time when Singapore faced international pressure to not execute Nagaenthran K. Dharmalingam, a Malaysian drug convict who reportedly had both low IQ and an alleged intellectual disability.

His family remembered him as "a gentle older brother, a doting uncle, a loving son" in their statement made after Abdul Kahar died; they were also heartbroken over his death.

A candlelight vigil was held outside Changi Prison and attended by Kirsten Han and several of her supporters and fellow activists during the early hours of 30 March before dawn on the day Abdul Kahar was hanged.

[24][28] Both the European Union (EU) and Amnesty International, in response to Abdul Kahar's execution, criticised the decision to hang Abdul Kahar, as they claimed that the death penalty failed to act as an effective deterrent to crime and was a cruel and unusual punishment; they also stated they will continue to push for Singapore to resume its moratorium and abolish the death penalty in accordance to the international trend.

[29][30] Citing the two unrelated cases of Abdul Kahar and Nagaenthran, the Global Commission on Drug Policy stated that the death penalty was an inappropriate response to any offences, including drug-related crimes.

[31] The ASEAN Intergovernmental Commission on Human Rights (AICHR) was also criticised for keeping silent and not intervening on the issue of Abdul Kahar's death penalty.

[33][2] When the Speakers' Corner at Hong Lim Park was re-opened in April 2022 due to the easing of COVID-19 restrictions and rules, a protest was conducted at the park to show opposition to the government's use of the death penalty in light of both Abdul Kahar's execution and Nagaenthran's failed appeal, and 400 Singaporeans and PRs, including activists Kirsten Han, Kokila Annamalai and Jolovan Wham, attended the event.

[34][35][36] Despite the fact that Singapore faced international pressure to not carry out their pending executions of drug traffickers, it was revealed earlier in the same month Abdul Kahar was executed, a 2021 survey result showed that more than 80% of Singaporeans believed that the death penalty should remain in Singapore due to its deterrent effect and relevance in fighting crime, and the government maintained its stand that the death penalty is effective in deterring serious crimes through its parliamentary findings the year before.