A poster of the documentary The Sinking of the Lisbon Maru. [Photo/Tide News]

As of 3 pm on Sept 23, the national box office of the documentary The Sinking of the Lisbon Maru has exceeded 26 million yuan ($3.71 million), according to Maoyan Pro data, a platform for ticketing, box office tracking, and big data analysis in China.

Since its nationwide release on Sept 6, the documentary, which tells the story of how British prisoners of war were saved by Zhoushan fishermen during World War II (1939-45), has seen its box office and popularity soar.

In Zhoushan, this once-forgotten piece of Dongji Island's history has become a sensation among moviegoers. According to the publicity department of the Zhoushan committee of the Communist Party of China, local cinemas have reported that the majority of their recent box office revenue comes from the film.

In its 18 days of release, the film has accounted for an average of 36.9 percent of daily box office revenue in the city, peaking at 71.6 percent in one day, and 13.1 percent of daily screenings, peaking at 18.7 percent.

The film was the fastest-selling at the 26th Shanghai International Film Festival and has garnered significant praise from industry professionals since its premiere.

"The director has brought this poignant story to life, unearthing a little-known piece of history," said Hu Mu, a Zhoushan native and one of the film's planners.