Hundreds of Cambodians have paid their respects to Ta Mok, a former Khmer Rouge leader nicknamed "The Butcher".
Ta Mok died ahead of a tribunal on the Khmer Rouge regime
In a traditional Buddhist funeral ceremony, incense was burned and prayers recited over Ta Mok's body, which was daubed with white powder.
The ceremony took place in Ta Mok's former stronghold of Anlong Veng, in the north of Cambodia.
Ta Mok, who died on Friday, was the regime's military commander and linked to many atrocities of the 1970s.
About 1.7 million people died under the Khmer Rouge, through a combination of starvation, disease and execution.
Ta Mok was the only Khmer Rouge leader who refused to bargain with authorities following the collapse of the regime, and he was arrested in 1999 near the Thai border.
He was transferred to hospital from prison last month, suffering from high blood pressure and tuberculosis.
Ta Mok died in the capital Phnom Penh. His body was transported to the house of one of his daughters in Anlong Veng, some 305km (190 miles) north.
Here Ta Mok ruled as a local warlord in the late 1990s, after the Khmer Rouge were forced out of the capital.
Though Ta Mok was one of the most vicious leaders of the Khmer Rouge, he is remembered in this area as tough but generous - a man who brought public works projects and some employment to a poor region.
On Saturday, local people filed through the house to light incense and contribute money towards his funeral, as 11 Buddhist monks sat in attendance.
Ta Mok received the funeral blessings he denied so many others
"He is the one who allowed me to survive," a weeping Sarann Chanthy, 50, told the news agency AFP.
"When I heard the news that Ta Mok died, I was shocked and cried until I fainted," she said.
"He was very important for the villagers in Anlong Veng. Sometimes in the past I was angry with him over something, but I've lit incense to pray for his forgiveness - I wish him to go rest in a better place," she said.
Correspondents say there is an irony in Ta Mok being given a Buddhist funeral. Religion was banned under the Khmer Rouge, with bodies thrown unceremoniously into mass graves and no mourning allowed.
Negotiations between Ta Mok's family and authorities are under way to decide where he should be buried. His family are thought to favour a burial on the grounds of his former home in Anlong Veng.
Ta Mok was expected to be one of the first people tried for genocide and crimes against humanity at UN-backed hearings due to start next year.