ACT Police have warned people not to click on a video being posted to various Canberra buy, swap and sell Facebook pages, which is believed to contain child exploitation material.

A still frame of the video examined by police led them to believe that it contained material that could be illegal.

They have told people not to click on the video, which may appear in the Facebook feeds of those who follow buy, swap and sell groups in Canberra.

Police said people may find the images distressing.

They urged Facebook users not to forward the video, even to police, as sharing child exploitation material may constitute an offence.

Police instead encouraged people who came across the video to report it to Facebook, which would alert the relevant authorities.