BEIJING - A Chinese archive official on Monday refuted claims that confessions written by Japanese war criminals were extorted by forced or coercive measures, calling them "totally unfounded".

"The Chinese government rendered humanitarian treatment to the Japanese war criminals and roused their conscience," Li Minghua, deputy director of the State Archives Administration (SAA), said at a press conference.

Li said most of the Japanese war criminals released from China have joined activities to promote friendly exchanges between the two countries and expressed penitence of their wartime crimes after they returned to Japan.

"If China had forced them to write these confessions, then how could we force them to repent in Japan?" Li asked.

Also, Li said confessions by some of the criminals covered only a small part of their wartime crimes, evidence that they were not under pressure from China when writing the confessions.

To mark the 70th anniversary of the end of World War II, Li said the SAA is planning to release a series of books, online videos and TV documentaries of relevant historical archives and documents, including a compilation of Japanese war criminals' confessions obtained by Chinese prosecutors in the 1950s.

"These documents reveal wartime atrocities by Japanese aggressors in China, such as killing sprees, looting and crimes of producing and using bacteria and chemical weapons, testing biological weapons on living Chinese people and forcing Chinese into labor or sexual slavery," he said.

Also, another 100-volume book on selected Japanese war criminals' confessions, with photocopies of the original manuscripts in Japanese language, Chinese translations and an abstract in English, will be published in August, the official said.

The administration will also publish books of documents on the cooperation between Chinese and American troops in fighting Japanese enemies in WWII as well as on the contributions of anti-Japanese forces led by the Communist Party of China in the war.