
The body of Boonserm Charoensuk, 70, was found by residents of Soi Udomsuk 26, section 47, when they were digging a hole on the unused, grassed land behind an apartment building on Tuesday evening.
They found a leg poking out from the ground, so they alerted officers at the Bang Na police station.
Police and staff of the Poh Tek Tung Foundation as well as a doctor from Chulalongkorn Hospital found the body wrapped in a blanket and buried.
Police questioned local residents and learned that an old woman who was living with her son in a rented room at the apartment building had not been seen for over a month.
Police then questioned the son, Lert Yungyuen, 53, and he admitted that he had buried his mother there after she died of old age on July 25.
He said he could not afford a funeral and did not inform the authorities of the death.
The body was sent for an autopsy at the Forensic Medicine Institute at the Police Hospital.
Bang Na police deputy chief Pol Lt-Colonel Thirapong Naksuk said on Wednesday that police had to charge the son for failing to inform the authorities about the death and for unlawfully concealing a body.
The cost of a funeral service in Bangkok is said to be at least Bt20,000.