Cambodia's opposition leader Sam Rainsy, who has been in self-imposed exile for a year, has been given a pardon by King Norodom Sihamoni.
Sam Rainsy has been an outspoken government critic
In December, a court sentenced Mr Rainsy in absentia to 18 months in jail for defaming the leaders of the governing coalition.
The surprise request for a pardon came from his long-time adversary, Prime Minister Hun Sen.
Mr Rainsy went to France last year after losing immunity from prosecution.
On Friday, Mr Rainsy and Hun Sen agreed to make an effort at reconciliation.
Opposition MP Cheam Channy, who has spent a year in prison, was also pardoned and was expected to be freed on Monday.
Prime Minister Sen's adviser Om Yentieng told AFP news agency that both men will likely have their parliamentary immunity reinstated.
Mr Rainsy had accused Hun Sen of involvement in a grenade attack on an opposition rally eight years ago. But a court ruled there was no evidence to support the accusation.
Prime Minister Hun Sen has accepted an apology from Sam Rainsy
The court also found Mr Rainsy guilty of defaming Prince Norodom Ranariddh, the National Assembly president, by accusing him of taking bribes to have his royalist Funcinpec party join Hun Sen's government.
In a surprise exchange of notes on Friday, Sam Rainsy, from his exile in Paris, apologised to Hun Sen for making the accusations, and Hun Sen accepted the apology, signalling a truce in their long-running feud.
The BBC's Guy De Launey in Phnom Penh says a forthcoming meeting with Cambodia's major donor countries may have influenced events. The international community had been highly critical of the arrests of opposition figures.