The Senate on Monday voted to reject a police request that it to allow Mae Hong Son senator Boonsong Kowawisarach to be questioned about the fatal shooting of his former wife.
The police request was taken up for consideration as an urgent issue, only to be turned down on the grounds that the senator is protected by parliamentary immunity and that the parliament will go into recess only one month from now.
Mr Boonsong, 56, is wanted for questioning by Wang Chin district police over the fatal shooting at a restaurant in Phrae province on Aug 12.
The senator was reportedly removing ammunition from his gun when it discharged. The bullet hit his 46-year-old former wife Chanakarn Dedkhad in the abdomen. She died on the way to hospital.
Mr Boonsong is facing a charge of manslaughter.