Media playback is unsupported on your device Media caption Students and staff at Centre NAD were "surprised" when the video went viral

A video of a golden eagle snatching a child in Canada that has gone viral online was an elaborate hoax aimed at testing the skills of the clipmakers.

The video shows the bird briefly lifting the child in a Montreal park before dropping him unharmed.

Nearly 17 million people have watched the video on YouTube in three days.

But a digital training centre in Montreal later told the BBC that the clip was made by its students as part of a degree course.

Suzanne Guevremont, director of the Centre NAD, said the clip had been produced by four students who "had an idea of making something believable".

The students - who were doing a degree in 3D animation and digital design - had come up with the idea after a brainstorming session, completing the project in seven weeks, she said.

"It's a challenge... they wanted to test their skills," Ms Guevremont said.

She added that the bird and the child seen being snatched were all computer generated imagery (CGI), and the only real things in the video were the park, the boy (after being dropped on the ground) and his father comforting him.

The CGI was dropped into real footage to create the effect.

Some YouTube and Twitter users expressed doubts about the authenticity of the clip soon after it was posted online on 18 December.