Public prosecutors have decided not to indict three suspects for the shooting murder of a former mayor of Songkhla municipality due to insufficient evidence.
The suspects are still at large.
Pol Col Sumit Srinual, chief of Songkhla police, said the prosecutors made their decision on Tuesday.
However, police can appeal the issue to the Songkhla governor if they decide to oppose the prosecution office's decision. The three suspects in hiding are Pramote Sang-arun, Chayan Nupan and Natthaporn Nakray.
Police said Mr Pramote is the president of the Tha Bon tambon administration organisation in Ranot district of Songkhla.
Police charged him with masterminding the murder of former Songkhla mayor Peera Tantiseranee.
Mr Natthaporn was the driver for Kitti Chuchuay, who is also suspected of plotting the murder.
Mr Peera was gunned down in a drive-by shooting on Nakhon Nai Road in Songkhla's Muang district on Nov 7 last year. A police decision on whether to accept the outcome is pending.