Police and court officials raided the Phnom Penh headquarters of the Khmer Power Party yesterday and seized documents and computers, saying they believed they would find proof that the party’s jailed leader Sourn Serey Ratha was conspiring with another prominent dissident to form a government in exile.

Serey Ratha was arrested on Sunday and charged with inciting disobedience in the military, demoralising the military and inciting a felony over a Facebook post criticising last week’s deployment of troops to the Lao border, which he said would only put soldiers in harm’s way while top generals relaxed with women.

The KPP leader’s deputy, Suong Sophorn, was yesterday morning preparing a press conference at the party’s headquarters in Tuol Kork district to announce that Serey Ratha was no longer the leader – in order to avoid the party’s dissolution due to his presumptive coming criminal convictions – when police began the raid.

A Phnom Penh Municipal Court official read aloud a document signed by Deputy Prosecutor Sieng Sok ordering the raid to find evidence against Serey Ratha, explaining they believed he was working with self-exiled Khmer National Liberation Front leader Sam Serey in his efforts to form a shadow government.

The official said a statement condemning the arrest on Monday by Serey – whom the government accuses of being a terrorist, as they once did the then self-exiled Serey Ratha before his pardon in mid-2015 – had led prosecutors to believe the two were conspiring and they were seeking more evidence.

Speaking after the raid, Sophorn said any statements released by the KNLF leader – who did not respond to requests for comment but has in the past maintained that he seeks only peaceful change in Cambodia – was not evidence that Serey Ratha was working with him.

“It’s just a little letter from Sam Serey, and they accuse Sourn Serey Ratha of having an agreement together with him,” Sophorn said, describing the case against Serey Ratha as far-fetched. “One story has not yet ended and then we have another story to add.”

In a speech on Monday, Prime Minister Hun Sen accused Serey Ratha of insulting King Norodom Sihamoni and said documents would show the KPP leader was trying to prove the King was also a French citizen. Insulting the monarchy is not itself listed in the Criminal Code, though the Constitution says the monarch is inviolable.

The KPP’s Sophorn said yesterday that changes to the Political Parties Law allowing for the dissolution of parties that “conspire” with criminals should not now apply, as the KPP had completed the procedures passing leadership from Serey Ratha to Sophorn in an acting capacity, severing the party from the alleged criminal.

“We already issued a statement saying that what Sourn Serey Ratha said was his personal business only,” he said. “The Facebook of Sourn Serey Ratha belongs to Sourn Serey Ratha. These words were not posted to the page of the party.”

However, Interior Ministry spokesman Khieu Sopheak said by telephone that the decision of whether or not to dissolve the KPP in the likely case that Serey Ratha is found guilty after his trial on August 24 would have to wait until after a verdict.

“Wait to see Sourn Serey Ratha sentenced first. He is not yet a convict,” he said, declining to comment further.

Sok, the deputy prosecutor, declined to comment on the raid, but confirmed reports that Serey Ratha’s bodyguard had been arrested alongside him on Sunday on suspicion of drug use and weapons possession, but he was released to a drug rehabilitation centre yesterday after the weapon was found to be a “toy”.