A former Cambodian soldier has been charged with murder in the killing of a prominent government critic, an attack that has raised accusations of a political conspiracy.

Oeut Ang faces up to life in prison if convicted of killing Kem Ley, who was shot dead on Sunday. He also was charged with possession of an illegal weapon when he appeared at the Phnom Penh Municipal Court on Wednesday.

During interrogation, Oeut Ang had told police that Kem Ley owed him $3,000, and that he shot the well-known political analyst and government critic because of the dispute.

He also identified himself by the nickname Chuob Samlab, which in Cambodian means "meet and kill." Court officials said the nickname would be used in documents for now.