Police have warned social media users not to share a video believed to depict child pornography and which appeared on numerous online buy, swap and sell pages on Sunday.
ACT Policing said the video had appeared on Facebook feeds of people who were members of various online marketplace groups for Canberrans.
The still image of the video indicated it contained child exploitation material, and police urged people not to click on it because they might find the images distressing.
They also warned users not to the forward the video or any images associated with the video to anyone, including police or Crime Stoppers, as they risked being penalised for the offence of forwarding child exploitation material.
An ACT Policing spokeswoman encouraged anyone who came across the video to report it to Facebook, which could alert authorities and remove the post from the user's feed.