
Provincial Police Region 5 commissioner Lt Gen Somkid Boonthanom
Tharit Pengdit affirmed that the DSI probe was proceeding appropriately with the help of two senior public prosecutors.
He said DSI investigators had found new evidence including witnesses and objects that implicated the five accused.
One of the five, Provincial Police Region 5 commissioner Lt Gen Somkid Boonthanom, voiced doubts this week about the credibility of the witness, who was a defendant who avoided a life sentence in another murder case.
But Tharit said there was no law prohibiting a defendant in one crime from testifying in another case. He said it was up to the judge if the testimony was convincing or not.
Tharit said the DSI had not arrest the witness for police (to question) because it had no authority to arrest or detain suspects for police inquiries.
"Pol Lt Gen Somkid has a constitutional right to fight the court trial and testify, as well as comment about DSI work but what I can confirm is that the DSI is working honestly," he said.
Asked if it was necessary to call Lt General Chalor Kerdtes, a former senior police officer now on death row after being convicted of the 1994 abduction and murder of two Srithanakhan family members, as a witness, Tharit said the alRuwaili case had many witnesses but he could not give details.
If the DSI wanted to get Chalor to testify, they would go through a process for court permission as required for other convicts, without giving him privileges or any assistance to escape, he said.
The Saudi Arabian charge d'affaires in Thailand had made a request on Tuesday for the DSI to work on the search for stolen Saudi jewellery because they saw a lot of progress in DSI work on other Saudirelated cases, Tharit said.
DSI deputy chief Suchart Wonganantchai, who headed the inquiry into alRuwaili's disappearance and the murder of Saudi officials here, would be assigned to the search for the stolen jewellery, he said.