The ringleaders of the Bali Nine were executed in Indonesia for attempting to smuggle 8.3 kg (18 lb) of heroin to Australia in 2005.

The Bali Nine were a group of nine Australians convicted for attempting to smuggle 8.3 kg (18 lb) of heroin out of Indonesia in April 2005. The heroin was valued at around A$4 million and was bound for Australia. Ringleaders Andrew Chan and Myuran Sukumaran were sentenced to death and executed on 29 April 2015. Six other members, Si Yi Chen, Michael Czugaj, Tan Duc Thanh Nguyen, Matthew Norman, Scott Rush and Martin Stephens, were sentenced to life imprisonment whilst another, Renae Lawrence, received a 20 year sentence. She was released after the sentence was commuted in November 2018. The Indonesian authorities reported on 5 June 2018 that Tan Duc Thanh Nguyen had died of stomach cancer. In November 2024, Prime Minister Anthony Albanese sought the repatriation to Australia of the remaining five members of the Bali Nine. On 15 December 2024, the five remaining members of the group were repatriated to Australia, and their life sentences were commuted with immediate effect.

Heroin, also known as diacetylmorphine and diamorphine among other names, is a morphinan opioid substance synthesized from the dried latex of the opium poppy; it is mainly used as a recreational drug for its euphoric effects. Heroin is used medically in several countries to relieve pain, such as during childbirth or a heart attack, as well as in opioid replacement therapy. Medical-grade diamorphine is used as a pure hydrochloride salt. Various white and brown powders sold illegally around the world as heroin are routinely diluted with cutting agents. Black tar heroin is a variable admixture of morphine derivatives—predominantly 6-MAM (6-monoacetylmorphine), which is the result of crude acetylation during clandestine production of street heroin.