Sam Walker: Prisoner posted YouTube videos of life behind bars
More action is needed to stop mobile phones entering jails after a prisoner was able to set up a YouTube channel from his cell, a union says.
Prison Officers' Association chairman Mark Fairhurst said it was "frustrating" prisoners were finding "ingenious" ways to hide phones.
Drug dealer Sam Walker was found using a smuggled phone to run a YouTube and Twitter account from Leeds jail.
Mr Fairhurst said body scanners and signal-blocking technology were needed.
The Ministry of Justice said Walker had since been moved to HMP Peterborough, but his social media activity has apparently continued.
His Twitter account has more than 19,000 followers and carries the description "unofficial account being run until Sam's home".
It also links to a YouTube channel, which carries videos captured in Leeds.
One video, published on 10 August, purportedly shows Walker in a room with Charles Bronson.
A caption alongside the video said: "Big Charlie Bronson becomes camera shy while I video him. All 6ft5ins & 20 stone of him."
The Ministry of Justice later clarified the prisoner in the video was not the notorious armed robber.
Mr Fairhurst said prison staff believed somebody outside the jail was posting the material on Walker's behalf.
He said prison officers had tried and failed to find a phone in Walker's cell, and he may have concealed it "in his person".
He said: "What we need is for the officers to get in that cell and get [the phone] off him, but they have ingenious ways of hiding mobile phones.
"If in fact he uses the popular choice, and he secretes the mobile phone in his person, we do not have the authority to take it from him.
"We're very reliant on storming in his cell and getting it while he's using it. It is very frustrating."
In 2018, 36-year-old Walker also posted videos while on the run in Sierra Leone before his eventual arrest.
Yet despite the move, his social media activity has continued, with the prisoner posting a photograph of himself at the jail.
A spokesman for Sodexo, which runs the jail in conjunction with the MOJ, said "immediate action" had been taken, but declined to say what form that action took.
Twitter and YouTube have been approached for a comment.
Mr Fairhurst said: "Realistically, as we've been highlighting, we want the technology in our jails to prevent mobile phone signals.
"That technology is available. It can isolate specific points in a prison. Of course, it costs money. I get the impression it's all down to funding."