Public prosecutors have indicted six suspects over the drowning death of actress Nida "Tangmo" Patcharaveerapong on Feb 24.
Nonthaburi provincial prosecutors announced the decision yesterday, after having postponed it three times.
The six are speedboat owner Tanupat "Por" Lerttaweewit, Phaiboon "Robert" Trikanjananun, Wisapat "Sand" Manomairat, Nitas "Job" Kiratisoonthisathorn, Tangmo's manager Idsarin "Gatick" Juthasuksawat and Peam "Em" Thamtheerasri.
The court released the suspects on bail after they were indicted.
Mr Peam was not in the speedboat when the actress fell into the Chao Phraya River and drowned, but he allegedly advised the other passengers to delay giving statements to police.
Tangmo's mother, Panida Siriyuthayothin, filed the case against the six with Nonthaburi police.
Office of the Attorney-General deputy spokesman Prayuth Petchkhun said that prosecutors decided to indict Mr Tanupat on five charges: recklessness causing death; giving a false statement; driving a boat without a licence; dropping objects into the river; and illegally taking the anti-anxiety drug alprazolam, a category 2-listed psychotropic medication.
Mr Phaiboon was indicted on four charges -- recklessness causing death, driving a boat with an expired registration, driving a boat without a licence, and dropping objects into the river.
Ms Wisapat was charged with recklessness causing death.
Mr Nitas was indicted on three charges -- recklessness causing death, assisting others to avoid punishment or receive less punishment, concealing evidence, and dropping objects into the river.
Ms Idsarin was charged with recklessness causing death, giving a false statement and assisting others to avoid punishment or to receive less punishment, and concealing evidence.
Mr Peam was charged with directing others to make false statements and assisting others to avoid punishment or receive less punishment, and concealing evidence.
Tangmo, 37, fell into the Chao Phraya River near Pibul 1 pier in Muang district of Nonthaburi on the night of Feb 24. Her body was found two days later.
Ms Panida earlier withdrew a murder case against the suspects.
Mr Prayuth said the police case report did not show any evidence of murder.
Police yesterday took the six suspects to Nonthaburi Provincial Court for arraignment.
In April, police forwarded their investigation report into the death of the actress to public prosecutors, having concluded the actress' death was caused by the reckless actions of others in the boat. They asked the prosecution to indict the six suspects on charges including reckless endangerment causing death.
Police earlier said investigators were convinced by evidence and witness statements that Tangmo died after falling into the river from the back of the speedboat at 10.34pm that night.