Miriung was born at Poma village in the Kieta district of Bougainville and was educated at the Tunuru Catholic Mission and at Chabai.
He differed with the PNG Government on a resolution to the conflict, condemning their attempts to end the war through a military offensive and extrajudicial killings, while supporting a more expansive concept of autonomy than the national government, eventually coming out in support of an eventual referendum on independence months before his death.
Shortly before his assassination, Papua New Guinean defence minister Mathias Ijape blamed Miriung for a BRA attack on PNG soldiers and called for his resignation as Premier.
A Commission of Inquiry was held under retired Sri Lankan judge Thiruvukkarasu Suntheralingam, which found in December 1996 that the murder was committed by several members of the PNGDF in conjunction with their allies the Siwai Resistance.
In December 2019, Miriung's eldest son Justin stated that the family believes that some figures from the national government were involved in his murder.