Boonsong Kowawisarat. (Senate of Thailand/HO)

A Thai senator accidentally shot and killed his personal secretary with a submachine-gun at a restaurant Sunday night, police say.

Mae Hong Son senator Boonsong Kowawisarat was eating at a restaurant in Phrae province with his personal assistant and cousin Chanakarn Detkard when Boonsong, 55, took out his gun, the Bangkok Post reported. Boonsong told police the gun accidentally went off and shot Chanakarn, 46, in the stomach.

Boonsong told police he was so shocked by what had happened that he couldn't take Chanakarn to the hospital himself. The restaurant owner took her to the hospital, where she was pronounced dead, the Bangkok Post reported.

Boonsong will be charged with causing death by negligence but, because he and Chanakarn were relatives and it was an accident, he is unlikely to be sued by his cousin's family, local police told Agence France Presse.