Former Cambodian People’s Party president and Senate President Chea Sim’s body was cremated on Friday in an elaborate Buddhist ceremony in Phnom Penh’s Wat Botum park.

Shortly after 7am, the golden casket containing the former CPP factional heavyweight, for many years considered the second-most powerful man in government after Prime Minister Hun Sen, was moved from his house to the cremation site in a lavish 3-kilometre procession that featured nine floats lacquered with gold, musicians, honour guards and monks.

Pro-government civil society groups, such as the Cambodian Red Cross and Cambodia scouts, marched alongside.

While Norodom, Sihanouk and Sothearos Boulevards were lined with mourners all the way to the funeral pyre at Wat Botum, they rarely formed more than one layer and tended to peel off as the procession continued past.

Once at Wat Botum, honour guards and officials outnumbered spectators, who numbered in the low hundreds.

Among attendees were Hun Sen, King Norodom Sihamoni, Queen Mother Norodom Monineath, newly elected Senate President Say Chhu and National Assembly President Heng Samrin as well as foreign diplomats.

Delivering a eulogy, Hun Sen, dabbing at tears, said the loss of Chea Sim, who died at age 82 on June 8 after long suffering from high blood pressure, diabetes and other ailments, was distressing and heartbreaking.

"The passing of Samdech Chea Sim is a loss of the top leadership dignitary of the nation, people and the CPP," he said, according to an English copy of his speech.

"Throughout his life, Samdech Chea Sim had been struggling for national independence and especially overcoming every obstacle for national salvation, building peace, national reconciliation, defending, rehabilitation and development of Cambodian motherland."

The funeral finished just before 11am, with King Norodom Sihamoni lighting the funeral flame, a moment marked with a barrage of celebratory rockets, which temporarily masked the crowd in a dense white haze.

The government previously declared Friday an official day of mourning and public holiday, decreeing that flags be flown at one-third mast.

Tomorrow, the CPP will convene its 38th central committee congress to elect a new party president – already announced as Hun Sen.