The premier was fourth in command in the military junta ruling Myanmar, also known as Burma, and gained notoriety following an attack on the motorcade of a leading pro-democracy activist in 2003 which he is believed to have orchestrated, and which resulted in several deaths.
Although holding the prime ministerial post, Soe Win was in fact only fourth in command in the junta, and had little policy-making power. He is likely to be succeeded by the acting prime minister, Lieutenant-General Thein Sein.
Soe Win died at the age of 59, 12 days after returning from Singapore, where he underwent treatment over a period of six months. His death comes less than one month after his twin brother's passing.
The southeast Asian country's military leaders have come under increasing international pressure since a deadly crackdown by troops on pro-democracy demonstrators led by Buddhist monks in late September, in which the government says 10 people were killed. However, some reports say up to 200 people were killed by troops, and thousands of people were subsequently arrested.