"Sir Ivor Roberts, senior adviser at the Counter Extremism Project, said it 'beggars belief' they are on YouTube 12 years on.

He added: 'It’s sickening to think such material can be easily accessed by children and vulnerable adults — and essentially act as recruiting videos, glamourising and justifying a violent neo-Nazi cause.

'The laws requiring wealthy social media giants to prevent such harmful material from being broadcast are simply not robust enough.'"

"YouTube says it does not allow hate speech under its terms of service and removes any content that incites violence or hatred. But a joint investigation by this newspaper and the Counter Extremism Project found videos contravening this policy have been online for up to two years."