Mike Haines spoke out with other families pleading watchdog Ofcom to act over the site – which has three million members – that hosts videos showing the deaths of their loved ones.
The platform, which we are not naming, contains graphic images of murders, suicides and terrorist executions including footage of aid worker David, abducted while working at a refugee camp in Syria in 2013 before being beheaded the following year.
A call from devastated families, including David's daughter Bethany Haines and Mike, comes as the Office of Communications gets new powers to probe and fine platforms for hosting illegal material.
Speaking on BBC Breakfast, Mike said: "It's horrifying. It's like a drug. Once you've had your first taste, you want another taste. So you want to see more and it becomes more violent and more graphic and more disgusting.
image [https://cdn.magzter.com/1583517504/1742265282/articles/nFitbmyxtLqjuj8Ipysys/2471746437.jpg]
"Every second that we delay in shutting this site down, we are endangering our youth."
Bethany, from Perth, said the comments on the videos are horrendous.
She added: "For years I have been trying to keep track and report sites such as this one. I have a fear my son will one day see the video of his grandfather."
image [https://cdn.magzter.com/1583517504/1742265282/articles/nFitbmyxtLqjuj8Ipysys/6472621176.jpg]
Ofcom has spent the past 18 months since the Online Safety Act was passed drawing up the codes of practice that platforms have to follow.
The regulator can now exercise its powers to investigate and fine platfo...