Vietnam's Peoples' Supreme Court on Thursday rejected an appeal from three people who were found guilty of abusing a 14-year-old boy in the southern province of Ca Mau.
Huynh Thanh Giang, 30, will continue serving a 23-year sentence handed down by the Ca Mau People's Court in June.
During the trial, Giang was found guilty of "deliberately injuring" and "torturing" his employee, Nguyen Hoang Anh.
Giang's wife, 33-year-old Ma Ngoc Thom, will serve the same sentence. The court also maintained a one-and-half-year sentence against Lam Ly Quynh, their employee, for aiding the couple.
The court considered the trio's appeal after they filed requests for leniency in exchange for a guilty plea.
According to the indictment, in September 2008 Anh began working at the couple's shrimp farm in Ngoc Chanh Commune. Serious abuse began soon afterward.
Following Anh's rescue in May, details of his torture were exposed in testimony to neighbors and concerned members of the community, shocking and angering the public.
Police found that the couple had beaten and tortured Anh with various items like hot water, pincers, hot coals, and hammers on numerous occasions during his employment
The trial also raised questions about the local authorities' ability to detect such misdeeds.
Ca Mau's authorities censured the leaders of the Phu Hiep Hamlet and Ngoc Chanh Commune, which manages the hamlet, for failing to intercede sooner.