Phnom Penh Municipal Court prosecutor has summoned "acting president" of the Cambodia National Rescue Party (CNRP) Sam Rainsy for questioning over his claim Minister of Interior Sar Kheng supported a revenge plot against Prime Minister Hun Sen.

According the summons, which was dated Monday and received by The Post on Wednesday, Prosecutor Seng Kim Lak called Rainsy, who he referred to as a "suspect", to appear at the court on the morning of July 31.

The summons came after a complaint was filed by three lawyers, Hak Seakly, Pich Soriya, Chao Bun Huon, representing plaintiff Sar Kheng.

“The individual has to come following this summons on time and bring documents relevant to the case if possible,” the summons read.

Prosecutor Seng Kim Lak also informed the chief of Phnom Penh police of the case and told officers “to implement the case according to procedure”.

Last week, Sar Kheng, who is also deputy prime minister, filed a complaint over Rainsy’s allegation that Dy Vichea, the son of former police chief Hok Lundy, was plotting revenge against Hun Sen over the death of his father.

Rainsy alleged Hun Sen was behind the helicopter crash that killed Lundy in 2008. He also claimed Sar Kheng supported Vichea's bid for revenge.