Four of six suspects arrested over a brawl that resulted in the death of a disabled man are reported to be the sons of police officers, posing an immediate challenge to the investigation.
Police have assured they will treat the case with an even hand, saying links to the police force will not affect how the suspects are treated.
"The incident raises concerns over the prosecution because four suspects are reportedly the sons of policemen, but no matter who they are we will strive for justice," acting city police chief Sanit Mahathaworn insisted Monday. "Punishments will be based on facts."
The six men were arrested by Chokchai police after an altercation with bread deliveryman Somkiat Sichan, 36, who had difficulty walking, on Sunday morning turned violent. One suspect and the victim were injured. Somkiat was later pronounced dead at a hospital.
According to an eyewitness, Somkiat was stabbed in the neck by a suspect identified only as a man wearing red.
"I tried to stop them, but the men pointed their knives at me," said the witness, Methat Phonprasoet, who is also Somkiat's nephew.
Mr Methat was among Somkiat's relatives who urged authorities to handle the case fairly.
The four suspects reportedly related to officers are Thiraphon and Arin Yotphonganan, aged 21 and 20 respectively, Mek Phonkraison, 19, and Monmanat Saengpho, 22. All are believed to be the sons of officers attached to Metropolitan Police Division 4, which oversees Chokchai where the brawl took place.
The two other suspects were identified as Akkaradet Thatsana, 22, and an 18-year-old whose identity was withheld.
Somkiat's older sister, Thanchanok Sichan, said a police officer who claimed to be the father of one suspect met her to apologise. She "felt sympathetic" towards him but still demanded a fair investigation.
Somkiat, a father of two, helped Ms Thanchanok run her bread business for three years. His relatives said the man was never confrontational and had not been involved in a quarrel until he met the six suspects.
Somkiat had an altercation with the suspects following a motorcycle incident earlier on Sunday. Mr Methat said Somkait had told him about the incident, adding that Somkiat demanded an apology from the suspects who had also bullied him for his disability.
The six men later arrived at the bread shop, said Ananchai Chaidet, who operates a law firm near the shop on Soi Chokchai 4.
Mr Ananchai claimed he heard a woman, believed to be the girlfriend of one of the suspects related to an officer, tell the suspects to kill Somkiat during the brawl.
Mr Methat said he later arrived at the bread shop and found a bloody scene. After the arrest, one suspect reportedly admitted to police the group had been drinking alcohol prior to the incident.
Police are examining evidence including knives and a brick. Security camera footage is also being used to identify the cause of the incident.
Video footage will provide a clearer picture of the incident and whoever killed Somkiat will be charged with murder, Pol Lt Gen Sanit said. The suspects are currently charged with assault causing death and possessing weapons, Chokchai police say.