For the past three years the US-funded Cambodian Centre for Human Rights, founded by prominent local human rights activist Kem Sokha, has promoted awareness of democracy and human rights in the rural villages and towns of impoverished Cambodia.

But in recent days Mr Kem Sokha and two other high-profile human rights activists were arrested on charges of defaming long-time prime minister Hun Sen, renewing concerns about the future of democracy in this troubled country.