Cambodia National Rescue Party lawmaker Nhay Chamroeun has engaged a lawyer to join a lawsuit in the US against the prime minister’s eldest son, Lieutenant General Hun Manet, and the Cambodia government.

The attorney pursuing the case, Morton Sklar, said Chamroeun had instructed him to sue the scion as well as the Cambodian state over his assault at the hands of members of Prime Minister Hun Sen’s Personal Bodyguard Unit outside the National Assembly on October 26 last year.

Sklar said he will attach Chamroeun’s complaint to the original case lodged by jailed opposition official Meach Sovannara, another dual citizen, who accuses Manet and the government of torture and wrongful imprisonment related to his incarceration for involvement in a violent 2014 anti-government protest.

“Nhay Chamroeun has officially authorized me to act as his attorney, and to join him as an additional Plaintiff,” Sklar said via email, adding the amendment would be filed soon with the federal district court for the Central District of California in Los Angeles.

Sklar claimed the violent attack against Chamroeun would bolster his team’s argument that Manet and the government were not protected by the Foreign Sovereign Immunity Act because the allegations fell within an exemption concerning torture and terror acts committed against US citizens.

Chamroeun, a dual US-Cambodian citizen, and fellow CNRP lawmaker Kong Saphea were set upon by a mob of at least 16 men who emerged from a pro-government rally. Three soldiers from the Prime Minister’s Bodyguard Unit were convicted, though evidence pointed to wider involvement from the elite corps, of which Hun Manet is a deputy commander.

Manet’s lawyers in the US have moved to dismiss the case, claiming that he was not properly served and is not subject to the court’s jurisdiction.