BEIJING - A Beijing-based American journalist makes a startling discovery in an upcoming book and film on his search for what became of a British submarine that sank off the Chinese coast in the 1930s.

Steven Schwankert learns that China raised the HMS Poseidon in 1972, apparently without telling the British or anyone else.

That revelation lies at the heart of his upcoming book, "The Real Poseidon Adventure: China's Secret Salvage of Britain's Lost Submarine," and an accompanying documentary film. The book is due out in 2013 from Hong Kong University Press.

The Poseidon sank on June 9, 1931, after the captain inadvertently turned into a Chinese cargo ship while conducting exercises.