HONG KONG — He was a towering figure of the 20th century, instrumental in building the Chinese Communist Party from the battlefield to the halls of power. He worked alongside Mao Zedong for decades, and was revered for his rich intellect and even temperament.

And as the first premier of the People’s Republic of China, Zhou Enlai met with Henry A. Kissinger in Beijing in 1971 to pave the way for President Richard M. Nixon’s groundbreaking trip to China the next year, beginning a new era in global politics.

Now, a book being published this week offers a radical reinterpretation of Zhou’s life: He was probably gay.

That assertion is sure to be contentious in China, where homosexuality is not widely accepted and where many may view it as an attack on Zhou’s character. Indeed, the book is expected to be banned in mainland China, as are other unauthorized biographies of Zhou.