PHNOM PENH - Two former Khmer Rouge leaders Thursday began appeal hearings against their landmark convictions for crimes against humanity last year which saw them handed life sentences by Cambodia's UN-backed court.
"Brother Number Two" Nuon Chea, 88, and ex-head of state Khieu Samphan, 83, were the first top leaders of a regime responsible for the deaths of up to two million Cambodians to be jailed.
But their lawyers quickly appealed, with Nuon Chea's team accusing the court of a string of errors and the judges of failing to remain impartial due to their personal experiences under the communist regime from 1975-1979.
The pair sat in court with their defence teams Thursday as 300 people watched the proceedings from the public gallery.
Nuon Chea, wearing his trademark sunglasses, later left the room to watch the proceedings remotely from a holding cell, with his lawyers saying he had back pain.
"In the name of the United Nations and the Cambodian people the (court) opens an appeal hearing of the parties against the judgement dated 7 August," Judge Kong Srim, president of the tribunal's Supreme Court Chamber, said.
The court is set to hear from three witnesses requested by Nuon Chea's lawyers - including at least two former Khmer Rouge officials - during hearings scheduled over the next two weeks.
According to a tribunal document, appeal judgements are expected during the first quarter of 2016.
Led by "Brother Number One" Pol Pot, who died in 1998 without ever facing justice, the Khmer Rouge dismantled modern society in their quest for an agrarian utopia and nearly a quarter of Cambodia's population was wiped out by starvation or execution.
The complex case against Nuon Chea and Khieu Samphan was split into a series of smaller trials in 2011 for reasons including their advanced age and the large number of accusations.
Their convictions last August followed a two-year trial focused on the forced evacuation of around two million Cambodians from Phnom Penh into rural labour camps and murders at one execution site.
The pair are also undergoing a second trial for genocide centred on the killing of ethnic Vietnamese and Muslim minorities, forced marriage and rape.
In its historic debut trial, the UN-backed court in 2010 sentenced former Tuol Sleng prison chief Kaing Guek Eav, alias Duch, to 30 years in prison - later increased on appeal to life - for overseeing the deaths of 15,000 people.
In March, the court charged three more former Khmer Rouge members with crimes against humanity, ignoring warnings by strongman Cambodian premier Hun Sen - a mid-ranking regime cadre before he defected - that further prosecutions risked reigniting conflict.