KUALA LUMPUR, Malaysia >> Singapore is due to hang a Malaysian man next week for smuggling a small amount of heroin into the country, but legal and human rights groups are urging the execution be halted because the man is intellectually disabled.

Nagaenthran K.Dharmalingam, then 21, was detained in April 2009 for trying to smuggle nearly 43 grams (1.5 ounces) of heroin into Singapore, found strapped to his left thigh. He was sentenced to death by hanging in November 2010 under Singapore’s strict drug laws.

Death penalty opponents say Nagaenthran’s IQ was disclosed during the trial as 69, a level that is internationally recognized as an intellectual disability. They say he was also found to have attention deficit hyperactivity disorder and a drinking disorder that together could affect his judgment, decision making and impulse control.

Nagaenthran’s appeal to reduce the penalty to life in prison failed and a final push for a presidential clemency was rejected last year.

A judicial hearing was set for Monday to hear arguments that executing a mentally disabled person would violate Singapore’s constitution. If the review fails, Nagaenthran will be the first person executed in Singapore since 2019.

Malaysian Foreign Minister Saifuddin Abdullah said Wednesday he has written to his Singapore counterpart about the case and would extend consular aid to Nagaenthran and his family. Singapore’s home ministry has defended the court’s decision, saying Nagaenthran clearly understood the crime and has exhausted all legal appeals.

His lawyer, M. Ravi, said Nagaenthran, now 33, “could possibly have a mental age below 18” and that the disability doesn’t allow him to understand or appreciate deterrence. “Therefore, we contend that the execution is irrational and a capricious act of the state,” he wrote on Facebook.

The Malaysian Bar and two other legal bodies this week submitted an appeal to Singapore to commute his sentence.

A group of lawyers, activists and human rights groups also rallied outside Malaysia’s Parliament this week, demanding government intervention. They said in their petition that it was “incredibly excessive” to hang Nagaenthran given his disability and that he was being punished for a non-violent crime.

The Anti-Death Penalty Asia Network, Amnesty International and Human Rights Watch echoed calls to save Nagaenthran, saying the execution of a disabled person violates international laws and won’t deter crime.

ADPAN said the failure to recognize Nagaenthran’s mental health “indicates a systemic failure in Singapore’s criminal justice system.” Amnesty said there are concerns of “multiple violations of international human rights” and fairness of the proceedings which could render his execution unlawful.

“Singapore should commute Nagaenthran Dharmalingam’s sentence and amend its laws to ensure that no one is subjected to the death penalty, certainly not people with intellectual or psychosocial disabilities,” Human Rights Watch said.

The clamor to commute the penalty is giving Nagaenthran’s family a sliver of hope.

His older sister, Sarmila Dharmalingam, said the family cried and wailed when they were informed of the execution on Oct. 26. Initially she kept it a secret from her mother, who at 59 still works as a cleaner and has health problems.

On Tuesday, two days before the Hindu festival of Diwali, 10 family members finally surrounded her to explain about her son’s imminent execution. She is set to fly to Singapore on Friday and is to meet her son for the first time in nearly three years.

“Instead of celebrating (Diwali), we are crying and thinking about my brother and counting the days,” Sarmila, 35, told The Associated Press in a telephone interview on Thursday from northern Ipoh town. “He has been on death row for more than 10 years. Please give him a second chance and stop his execution.”

Sarmila said Nagaenthran, the second of four siblings, is a loving person who took odd jobs during high school to help out the family. The family still finds it hard to accept the court outcome and is praying daily for a miracle, she said.

In 2019, she said Nagaenthran suddenly refused to meet or talk to the family. Lawyer Ravi also wrote on Facebook that Nagaenthran refused to meet him since 2019.

Nagaenthran finally opened up recently and reconnected with them on the day the family was informed of his execution. Sarmila said he was calm but had refused to talk about his silence in the past few years or about his imminent sentence.

She said their younger brother met Nagaenthran at a Singapore prison this week and found his behavior strange. Nagaenthran would stare at the ceiling, talk incoherently and jump from one subject to another, she said.

Sarmila said he appeared cheerful in a phone call Thursday and had asked how the family was celebrating Diwali.

“Ma, don’t worry. I will come back soon and we can celebrate together” she quoted Nagaenthran as telling their mother in the Tamil language, before cheekily asking for his “ang pow” — a monetary gift that elders usually give as a token of blessings.