Police have linked the body parts found floating in the Chao Phraya river to a Spanish businessman who was likely kidnapped and extorted before he was murdered.
The first body part was discovered on Sunday with six additional parts found since then at different locations along the river.
Pol Gen Panya Mamen, the senior advisor to the Royal Thai Police Office who is leading the murder investigation, told reporters on Thursday the victim was a Spanish businessman who entered Thailand on Jan 19.
"I am convinced that within the next 48 hours this case will be resolved and that all perpetrators are foreign gangsters -- although we suspect that some Thai nationals may have had knowledge [of the crime]," Pol Gen Panya said.
An official at the Spanish embassy said they had yet to receive confirmation of the victim's identity. The Bangkok Post is withholding the man's name until his family is notified.
Pol Gen Panya said the murder likely took place between Jan 25 and 27. Detectives are working on the theory that he was kidnapped and coerced before he was killed.
"Police have also detected that after his death (his killers) transferred his money to several countries including Singapore, Spain and within Thailand," he said.
Investigators initially struggled to identify the victim. Earlier in the week police said they believed the man was of Asian origin and suggested that Chinese triads might have been involved because of the method chosen to dispose of the body.
Ruam Katanyu Foundation staff members collect a body part found near the Rama V Bridge in Muang district in Nonthaburi on Tuesday. (Photo by Pattanapong Hirunard)