![](http://web.archive.org./web/20151003153700im_/http://www.smh.com.au/cqstatic/12z7v7/11887963_1459766520994167_82922073198189477_n.jpg)
The Australian Border Force has failed to stop a convicted criminal from operating an extremist website that incites and promotes violence and retribution from inside an immigration detention centre.
The private Facebook group appears to be operated by Roy Gilbert, a British national linked to ultra-violent prison gang Prisoners of War, who has spent the past five years in immigration detention.
The 41-year-old is also an associate of one of two men charged over the near-fatal shooting of a police officer in Moonee Ponds this year.
The page, which The Sunday Age has chosen not to name, is frequented by a number of known bikies and underworld associates who post threats against enemies and share images of mutilated corpses, guns, knives, cash and illicit drugs.
"Some don't mind a murder," Gilbert allegedly posted in August, when one member asked why the group was set up.
Calls are frequently made for revenge and retribution against police informers and "snitches", including family members of slain drug kingpin-turned-police informer Carl Williams.
Williams was bashed to death in Barwon prison in 2010 by Matthew Johnson, a notoriously violent inmate who heads the anti-informer Prisoners of War.
![Still from CCTV footage moments before Matthew Johnson kills Carl Williams in Barwon Prison](http://web.archive.org./web/20151003153700im_/http://www.smh.com.au/content/dam/images/g/k/0/g/q/9/image.imgtype.articleLeadwide.620x349.png/1443833976827.png)
Still from CCTV footage moments before Matthew Johnson kills Carl Williams in Barwon Prison. Photo: CCTV
A profile purporting to be Johnson is a member of the group, as well as a profile for convicted criminal Tommy Ivanovic, who was present when Williams was murdered.
Williams, along with his former wife Roberta, is called a dog while his father George is named as a crown witness. One post depicts a skeleton with a gun inserted in its mouth with the caption "snitches end up in ditches".
In July, the homes of Roberta and George Williams were targeted in fire bombings, and shots were also fired at Mr Williams' front fence.
The attacks gave rise to a police hunt that led to an officer being shot in the head while trying to intercept a suspect vehicle.
Johnson, Ivanovic and Gilbert are all linked through social media to Sam Liszczak, the 22-year-old charged over the shooting of the policeman and arson attacks.
The Australian Border Force has been aware of the existence of the page since at least July but has not blocked Gilbert's involvement.
Gilbert, who has extensive convictions for firearms offences and assault, is facing deportation after his visa was cancelled on character grounds and he was detained by immigration authorities.
A border force spokesperson said that although all detainees had access to the internet at detention facilities, the "inappropriate use of social media channels will not be tolerated, particularly if it involves offensive material."
The agency did not comment on why Gilbert was still able to access the page. A Victoria Police spokeswoman said the force had been aware of the page's existence since July and had asked Facebook to shut it down.
POW morphed out of a prison group called the Overcoat Gang, which ruled Pentridge Prison's H Division from 1975 until the early 1990s, and was founded by Mark Brandon "Chopper" Read.
![](http://web.archive.org./web/20151003153700im_/http://www.smh.com.au/cqstatic/12z7v7/RoyGilbert3.jpg)