Tens of thousands of Cambodians on Sunday joined the funeral procession of a prominent government critic whose murder in broad daylight has raised suspicions of a hit job in country with a long history of political violence. Kem Ley, a popular pro-democracy voice and grassroots rights activist, was shot dead on July 10 while drinking coffee outside a petrol station in the capital. The brazen murder sent ripples of fear across a country already brimming with political tension between strongman Hun Sen and a resurgent opposition. A former soldier charged with the murder claimed he shot Kem Ley over an outstanding debt. But suspicions of a political assassination continue to run strong in a nation where the rule of law is threadbare and critics of the elite are routinely silenced. On Sunday a massive crowd of mourners, many carrying portraits of Kem Ley, trailed for kilometers behind Buddhist monks and a motorcade carrying the 46-year-old's body in a glass casket. Thousands of others lined the streets to watch the procession, which marked the end of a two-week mourning period that saw people from across the country flock to the Phnom Penh temple where his body had lain. "He was a mirror of society, a hero. His murder is a huge loss to democracy," 39-year-old Hul Chan said while he was walking alongside other mourners. Many wore white shirts printed with Kem Ley's face and the words: "Wipe your tears, continue your journey." Sunday's procession, one of the largest public gatherings in recent years, will see the activist's corpse returned to his home village about 70 km south of the capital for burial. A regular critic of both Hun Sen and the political opposition, Kem Ley called for a new era of clean politics in graft-ridden Cambodia. The frequent radio commentator was also a major advocate for land and labor rights, traveling across the impoverished country to speak directly to villagers. He charmed Cambodians by speaking in a vernacular rich in metaphor and folk references, said Sebastian Strangio, the author of a recent book on the country's politics. "He had a very special gift for being able to explain complex issues to do with justice and accountability in a language that ordinary people could grasp," Strangio said. But stirring up opposition in the country's rural heartlands — for years considered Hun Sen's key support base — has long proved a dangerous game in Cambodia, he added. Watchdog groups say more than a dozen environmental activists have been killed in the past decade, often during efforts to expose illegal logging. Am Sam Ath, from the Cambodian rights group Licadho, said Sunday's outpouring of grief reflected a growing disillusionment with a government blamed for rampant rights abuses and corruption. "Kem Ley was a straight-talking person who strongly criticized social injustices," he said. "The people are standing up against injustice." Shortly before his death Kem Ley gave a lengthy radio interview welcoming a report that detailed the riches amassed by Hun Sen and his family during his three decades in power. United Nations rights experts expressed concern over the circumstances of his death "in view of his standing as a critic of the government." In a statement they said it "exemplifies an alarming negative trend in Cambodia whereby political activists and human rights defenders are facing increasing restrictions." Hun Sen has ordered a thorough investigation into the murder and urged people not to turn the case into a "political act."