Police have arrested three men in Sweden suspected of a gang rape that was livestreamed on Facebook.
Police in Swedish city of Uppsala have confirmed that the footage was seen by them.
Berggren told reporters that officials had seen "certain material", but, "We have not seen all the material that is said to exist", according to the Local. "But we don't have any images showing the attack itself".
The complex policies and ethical issues faced by Facebook LIVE and others were brought into focus after this latest graphic video was broadcasted.
The horrific assault reportedly took place in an apartment in Uppsala, Sweden.
Officers raided an apartment and took the suspects, aged 18, 20 and 24, into custody while they were still with the victim, aged 30.
The 21-year-old has spoken to the victim of the alleged attack to explain she had her support.
She said the victim's clothes were forcibly pulled off by three men, one of which was armed, before being sexually assaulted. He was putting the words in her mouth.
Another online witness told the paper: "At first I thought it was a poorly orchestrated joke".
'The first thing you think is 'how can you do such a thing to a girl?' And how can you do it live?
"It's screwed, totally sick", another member of the closed group told Expressen.
Instances of rape and torture have been streamed or posted on social media in the recent past, putting the social media platforms in a poor spotlight.
In an email to AFP, a press spokesman for Facebook in the Nordic countries denounced "a ugly crime".
According to Lovisa, there were 200 people watching the video at one point, before the police suddenly arrived on the scene and the video stopped, followed by sounds of commotion in the room.
In June 2016, Antonio Perkins, 28, also from Chicago, was shot dead while live-streaming a video of himself on the site.
The incident was reported by several viewers of "rape" which was broadcasted on Facebook LIVE. The gang shouted: "F*** Trump" and "F*** white people" during the attack, also in Chicago.