All five people on the speedboat with TV actress Nida "Tangmo" Patcharaveerapong when she fell overboard to her death last Thursday night will likely face charges of negligence leading to death and giving false statements to the police, according to a police source.
Her five companions were: Idsarin "Gatick" Juthasuksawat, Tangmo's manager; Wisapat "Sand" Manomairat; Nitas "Job" Kiratisoothisathorn; Tanupat "Por" Lerttaweewit, the boat owner; and Phaiboon "Robert" Trikanjananun.
Mr Tanupat and Mr Phaiboon have already been charged with operating an unlicensed vessel and negligence leading to death.
New evidence emerged when the Technology Crime Suppression Division (TCSD) traced Mr Tanupat's phone and found he had admitted to one of several people he consulted via phone that Mr Phaiboon was driving the speedboat when Nida fell off, a source at the Provincial Police Region 1 said on Wednesday.
Due to his lack of experience in manoeuvring the boat, Mr Phaiboon reportedly lost control of the boat, which prompted Nida -- who was in the back of the boat -- to grab hold of Ms Wisapat for fear she would fall into the river, said the source.
Afraid she would also be dragged into the river, Ms Wisapat claims she shook her legs, causing Nida to fall overboard, resulting in Nida's right thigh being hit by a blade of the boat's propeller, said the source.
The police will summon all five to face charges of negligence leading to death and providing a false statement to investigators, said the source.
Another source who is a member of the Provincial Police Region 1's team probing the Nida case, said Mr Nitas had given a conflicting statement about how the boat was operated that night.
He was the only witness who told investigators the boat jerked suddenly, causing Nida to fall into the river, said the source.
Mr Phaiboon was the only one who failed to attend the police's reenactment of Thursday night's incident, using a speedboat of the same model. He claimed he was suffering from high blood pressure, said the source.
In another reenactment, the police plan to take the exact same boat on the river to simulate the trip in exactly the same manner as it happened that night, based on the GPS record they retrieved from the boat, said Pol Lt Gen Jirapat Phumjit, head of Provincial Police Region 1.
The boat will run at the same speeds and on the same course as it did that night, and the investigators will test a claim by those aboard that they didn't hear any sound when Nida fell overboard, he said.
More DNA tests from samples collected on the boat will be handed to investigators soon and more witnesses will be questioned in addition to the 12 already interrogated, he said.
The phones of all six aboard the boat have been sent to the TCSD to find more clues, the second source said.