Photo released on Aug. 26, 2015 by the State Archives Administration of China on its website shows the image of Japanese war criminal Tadashi Hayashi.[Photo/Xinhua]

A Japanese World War II medical soldier said his "field training" involved watching a doctor put a prisoner into a "trance" before conducting a vivisection, according to a confession released Wednesday.

The State Archives Administration (SAA) published the hand-written confession by Tadashi Hayashi. Hayashi was born in 1920 and joined the Japanese War of Aggression against China in 1941. He was captured in August 1945.

Hayashi wrote that during one anatomy lesson for medical trainees, a military doctor injected a prisoner to put him into a "trance". The doctor then "dissected [the man] from chest to belly [...] while he discussed the major organs of the body."

Hayashi also confessed to fatally shooting a Chinese escapee, aged around 30, in Hubei's Zhongxiang county, in May 1941.

In November 1942, Hayashi watched another soldier inject water into the stomach of a Chinese prisoner and then broil him by fire. To prevent him from regaining consciousness, Hayashi stabbed the prisoner in the neck with a bayonet and another soldier stabbed him in the heart.

This was the 16th of 31 written confessions by Japanese war criminals to be published on the SAA website to mark the 70th anniversary of the end of WWII.