Head prosecutor Sompong Tangsiri said current evidence was not sufficient to put Napinthorn on trial. Criminal Litigation Department directorgeneral Sermkiat Woradit and national police chief Kowit Wattana had approved the decision.

Sompong said that although prosecutors had ended the case, investigators could reopen it and put Napinthorn on trial if they found new evidence within 20 years.

The victim's relatives, who were not happy and still wanted legal action against Napinthorn, could file a lawsuit because the prosecutors' decision did not affect the relatives' right to sue, he added.

The former senator's lawyer Manoon Sopha said Napinthorn - who was not present in court - still remained in Bangkok and did not want to sue the investigators because the prosecutors' order not to put him on trial was proof of his innocence.

Anont Phanrat, 40, Winyu Rattanawannee, 30, and Anantasak Srisawas, 42, will be tried on charges of premeditated murder, illegal possession of guns and ammunition and unauthorised carrying of weapons in public places.

Napinthorn had been implicated by one of the men, who admitted shooting Kobkul to repay Anantasak, a member of Muang Ratchaburi Municipality and the manager of Sri Muang Market, which is owned by Napinthorn.

The Nation