This is a picture of sadness, distress and misfortune. It just happens to be the wrong sadness, distress and misfortune.

A photograph of two crying Vietnamese children - taken nearly a decade ago - has been misappropriated on the internet as depicting the victims of last month's devastating Nepalese earthquake.

Vietnamese photographer Na Son Nguyen, who took the original, told the BBC it captured a brother and sister in the remote village of Can Ty, in Ha Giang province, in October 2007.

"The little girl, probably two years old, cried in the presence of a stranger so the boy, who was maybe three years old or so, hugged his sister to comfort her," he said.

"I was passing through the village but was stopped by the scene of two Hmong children playing in front of their house while their parents were away working in the field.

"It was both moving and cute, so I quickly made a shot."

Nguyen published the photo on his blog, but it has since taken on a new life as a generic poster of heartbreak. It has been variously described as depicting Burmese orphans, victims of the conflict in Syria, and now orphans of the earthquake in Nepal.

One Twitter user who shared the photo called it "the most divine picture of the century".

Two and a half year old sister protected by four year old brother in Nepal the most divine picture of the century! pic.twitter.com/tgHvHduPEe— Suresh Raina (@ImRaina) May 2, 2015

According to the BBC report, the photo's journey from a specific moment-in-time to all-purpose stock image began when it was shared on Vietnamese Facebook pages as a picture of abandoned orphans.

Nguyen told the BBC he tried to assert his copyright on the image and clarify its origin. But in the internet age, once something has gone viral, it can be very difficult to undo.

"This is perhaps my most shared photo but unfortunately in the wrong context," Nguyen said.

If a picture is worth a 1000 words.. This 1 of a brother protecting his sister in Nepal.. Is worth a million pic.twitter.com/hkREUXt8Wa— Farah Khan (@TheFarahKhan) May 2, 2015

My heart goes out to this brother protecting his sister in Nepal.. wish we could adopt them.. pic.twitter.com/evRCIo9g5j— Simi Garewal (@Simi_Garewal) May 1, 2015

More than 7500 people have died in the earthquake on April 25, Nepal's worst in more than 80 years. Just as foreign nationals have rushed out of the country following the devastation, the world's media have rushed in.

Nguyen observed on his Instagram count only weeks ago that photojournalism could not always be relied on and could be misrepresented.

"People believe them; but photographs do lie," he wrote. "Pictures just tell half truth, and the photojournalists must bring back the other half."