"I was very pleased to learn that the royal pardon was granted by His Majesty Norodom Sihamoni ... at the request of Prime Minister Samdech Hun Sen," Surya P. Subedi, special rapporteur on human rights in Cambodia, said in a release. "I now hope that with this development, the government will take the necessary action in order to allow Sam Rainsy to play a full part in the national politics of Cambodia."
Rainsy, leader of the Cambodia National Rescue Party, was tried in absentia in January 2010 on charges of destruction of property and racial incitement, then sentenced to 12 years in prison.
Rainsy has been in self-exile since 2005.
Subedi previously stressed the importance of a level playing field for all political parties to compete and had called for a solution to allow Rainsy to play a full role in Cambodian politics.
"Today I applaud the royal government of Cambodia for having taken this important step toward reconciliation, which is in the interests of stronger and deeper democratization of Cambodia," he said.
Cambodia's elections are July 28.