Bali Nine Myuran Sukumaran’s last act of kindness.

On the day of his execution in April 2015, Myuran Sukumaran was furious.

But it wasn't his own fate that he was angry about. Instead, he was furious about the treatment of the other death row prisoners who were about to face the firing squad with him.

Myuran's close friend, mentor and Archibald Prize winner Ben Quilty, said that the other inmates, who did not understand Indonesian, had been denied sufficient interpreters by Indonesian authorities.

"Myuran was very angry about this," he told news.com.au.

"The guards spoke a bit of broken English but all of the directions were given in Indonesian, and they [prisoners] relied on those people having a translator."

"Myuran and Andrew were translating Indonesian into English to try to help them understand what was going on," he added.

Watch: When the news broke Myuran Sukumaran and Andrew Chan were executed. Post continues after video.

Some of the prisoners, who were Iranian, Nigerian, Brazilian and Filipino, had very little understanding of what was happening.

Quilty said this was part of the reason that Sukumaran, Andrew Chan, and some of the other Bali Nine were the go-to guys in Kerobokan prison.

"If new inmates came in and they couldn't speak the language, men would be summoned and they'd help and negotiate their way through, right until the end."

Andrew Chan and Myuran Sukumaran. Image: Getty.

It's been almost a decade since Sukumaran and Chan were executed by a 13-member firing squad.

On the day of the execution, Sukumaran and Chan were marched out of the prison with a guard of honour. The other prisoners shook their hands and said goodbye, a testament to the positive impact they had made on the lives of the inmates.

As the two men and the other death row inmates stood in a row, ready to face the firing squad, Sukumaran and Chan led them in singing Bless the Lord O My Soul. They never got to finish the song.

Quilty had met Myuran three years earlier, when he received a note asking him about art technique. They soon formed a close bond. Quilty became his friend and his mentor, and he witnessed first-hand Myuran's development as an artist.

Another Day in Paradise forum series keynote speaker @benquilty surrounded by the powerful portraits painted by Myuran Sukumaran during his incarceration in Bali’s Kerobokan prison, and later on Nusa Kambangan Island

A photo posted by Campbelltown Arts Centre (@campbelltownartscentre) on Jan 13, 2017 at 7:08pm PST

"Myuran became an amazing young artist. Humanity was screaming off the walls," Quilty told the publication.

"There's a lot of people who thought these two young men deserved what was coming for them because they did the crime and therefore they have to do the time, but I challenge anyone to go and see it and come away with this feeling."

"He really did unpick all of the deep grief, horror and fear he was feeling in the studio," he added.

In April 2005, nine Australians were caught attempting to smuggle 8.3kg of heroin out of Indonesia and into Australia. And so became the Bali Nine — an infamous example of what can go wrong when messing with illegal drugs overseas.

Ringleaders Andrew Chan and Myuran Sukumaran were sentenced to death, while Matthew Norman, Scott Rush, Si Yi Chen, Michael Czugaj, Martin Stephens and Tan Duc Thanh Nguyen were sentenced to life in prison.

Renae Lawrence received a 20-year sentence after a successful appeal.

(Top, L to R) Myuran Sukumaran, Scott Rush, Tach Duc Thanh Nguyen, Renae Lawrence. (Bottom, L to R) Si Yi Chen, Matthew Norman, Michael Czugaj, Martin Stephen and Andrew Chan, at various stages of their trials in Denpasar in 2005 and 2006. Image: Getty.

Over the weekend, the five remaining members of the Bali Nine returned to Australia.

Matthew Norman, Scott Rush, Martin Stephens, Si Yi Chen, and Michael Czugaj arrived back in the country from Indonesia on Sunday.

The five men served more than 19years in prison.

Renae Lawrence walked free after serving almost 13 years in Bali's Kerobokan and Bangli prisons.

Tan Duc Thanh Nguyen died while serving time. In June 2018, the Indonesian Corrections Office confirmed that the 34-year-old died in a Jakarta hospital from stomach cancer on May 9.

After a last-ditch appeal to the Indonesian president for clemency failed, Andrew Chan and Myuran Sukumaran's executions were carried out on April 29, 2015.

Read more: The Bali Nine are back in Australia, 19 years after their arrest.

This article was originally published in January 2017,and has been updated since with new information.

Feature image: Getty.