Yong's Singaporean lawyer, M Ravi, who was in Kuala Lumpur on Thursday, told Malaysiakini he was in town to seek help from the public to show the Singapore government that Malaysians cannot tolerate Yong's execution or the death penalty.
Yong (pictured with his mother) was only 19 when arrested in 2007, outside the Meritus Mandarin Hotel in Singapore.
He was convicted on Nov 14 last year for drug trafficking and sentenced to death, which should have taken place on Dec 4.
However, Ravi, a prominent human rights lawyer, filed for a stay of execution on Dec 1, making it the first such case to be halted in the country.
When contacted, Ravi said he is aware why Singapore did not find it necessary to highlight Yong's case.
"Probably because he presents no political mileage. He is first of all a (Malaysian) Chinese, and a Sabahan," said Ravi in a telephone interview.
"But Malaysia can help by bringing the case to the International Court of Justice to determine whether Singapore's conduct constitutes a violation of both local and international laws and further seek a judgment," he said.
Ravi (right) said the mandatory death sentence in any country is tantamount to cruelty and violates international standards and human rights law.
Despite Yong's petition for clemency, Singapore Chief Justice Chan Sek Keong ruled on May 14 that Yong must go to the gallows.
"It is all wrong, because even a senior cabinet minister has said he should be hanged even before he had presented his petition," said Ravi.
According to Article 22(p) of the Singapore constitution, a petition is submitted to the president who then makes his decision on the clemency or mercy petition. President SR Nathan rejected the clemency petition last December.
When met in the Parliament lobby today, Minister in the Prime Minister's Department Mohd Nazri Abdul Aziz was in the dark about the case.
"This is the first time I heard about this case. What is it all about?" he asked.
When details were given, Nazri simply said: "It's in Singapore so we will not interfere in their legal processes."
Think Centre, a human rights NGO in Singapore, said the Court of Appeal has acknowledged that the mandatory death sentence is a cruel, degrading and inhuman punishment in other countries.
"But since Singapore's constitution does not provide for a prohibition against cruel, degrading and inhuman punishment, the legal system here (Singapore) seems extremely inhumane," said executive director Samydorai Sinnappan.
Activist Rachel Zeng, who has met Yong's family, said this was indeed one of the "saddest" cases in Singapore.
"I hope everything goes well with his appeal. We will do what we can to campaign along with the appeal," she added when contacted.
Zeng said Yong was permitted to see his mother through a glass panel last December. He knelt and bowed three times to her.
"It was really emotional as they have not seen each other for three years," said Zeng, who related the experience in her blog.
"They (Yong's family) did not tell her that her son is on death row in order to minimise the blow due to her (health) condition."
Zeng said she does not understand why the Singapore government and the attorney-general's chambers seem to be in a hurry to execute Yong.
"I also learnt just last Friday that there was another execution of a young man from Sabah (at the end of last November).
"Yong knew the young man as they were on death row together. It was a drug-related case as well," she added.
In Asia, apart from Singapore, only two other countries execute those who are found guilty of trafficking drugs - Malaysia and Thailand.