Bang Rak police identified the badly burned body of Mr Shinji Watanabe from his driving and social security card.
Thai PBS reports Police said they were alerted of the incident by security guards at the shopping plaza building at about 10.30 pm that a man whose body was in flames fell from the balcony of the fourth floor to the ground of the first floor
A rewind of video footages from CCTV cameras of the building and at the fourth floor showed he walked to the balcony of the fourth floor holding two plastic bottles and an energy drink bottle.
All three bottles were tied together with rope.
He sat on the balcony, poured gasoline from the three bottles to his clothes and set himself ablaze with torch lighter before falling down to the ground floor near the food centre where there were still many night shoppers in the building.
It was not immediately known the cause of the suicide attempt, but police established two theories, whether from work or love.
The police are contacting the Japanese embassy for help in establishing the exact cause and contacting his relatives in Japan.
Meanwhile, Police have recovered the fourth and final bag containing a human organ believed to be from missing Japanese man Yoshinori Shimato from Khlong Nang Thim canal in Bang Bo district.
Divers found the fourth bag at 5.40pm about two kilometers from the spot they had retrieved the third bag containing human body parts near a bridge across the Khlong Nang Thim canal close by Assumption University’s Bang Na campus off Bang Na-Trat Road
Pol Lt Gen Ruangsak Jaritek, acting assistant national police chief, said Tetsuo Shimato, son of the elderly Japanese man, had provided useful information.
There were three indications given by Mr Tetsuo to confirm the body found in the canal was his father. Among them were two dentures worn by the 79-year-old and a metal piece in his right knee.
Taxi driver Somchai Kaewbangyang and his wife Pornchanok Chaiyapa on Wednesday confessed to police they had dismembered Yoshinori Shimato at their house in Orchid Villa housing estate in Samut Prakan and placed the parts in four bags with sand before sinking them in the canal.