The Human Organ Transplant Act allows for the kidneys, heart, liver and corneas to be removed in the event of death from any cause for the purpose of transplantation. From 1 November 2009, HOTA will cover all Singapore Citizens and Permanent Residents 21 years old and above, who are not mentally disordered , unless they have opted out.

https://www.moh.gov.sg/content/moh_web/home/legislation/legislation_and_guidelines/human_organ_transplantact.html