Pol Col Sermpan Sirikong, superintendent of Phuket Police, told The Phuket News that 40-year-old Tourist Police Sen Sgt Maj Pinchai Piyadilok, had been questioned by police already but had refused to answer all questions put to him.
However, he had answered some of the questions police asked, Col Sermpan said.
Sgt Maj Pinchai remains in Songklanagarind Hospital in Songkla province, following amputation of his leg.
He faces two counts of murder and one of attempted murder in relation to the case.
Meanwhile, the other survivor of the mayhem, Natthapong Keawkuanchum, 25, is still yet to be questioned by police.
He has been discharged from Vachira Hospital and is now resting at home.
Col Sermpan told The Phuket News, “His mother refused to let the investigators question her son, because he needed to rest after his operation. After that, police visited to question him, but he was quite confused and he gave muddled answers.
“Officials will visit him again after Songkran – either this week or next week,” he said.
“I need both of them to speak to fill the gaps in the investigation. But I cannot force them to say anything. It is an important case. They have the right to refuse to speak prior to the court case.”
Police are also waiting for the results of forensic testing on the bullets and cases, which were sent to Bangkok to be examined.
When police arrived at the boarding house on March 20, they found 25-year-old Chalermpon Tripak dead on the bed in his room with one shot in the stomach.
Lying dead in a bloody heap next to the door was 25-year-old Saran Chaiyatham, shot in the left side of his chest.
Still alive on the bed, but with a stomach wound, lay Mr Natthapong.
Sgt Maj Pinchai Piyadilok was found slumped outside the door to the room.
At the time of the shooting, Phuket Police Chief Gen Choti Chavalviwat told The Phuket News that although all the details were not yet clear, Sgt Maj Pichai’s gun was the only one found at the scene, indicating he had fired the fatal shots.