The offenders are believed to have used secret mobile phones to upload bizarre racy snaps to Facebook and Instagram.

Several prisoners are pictured sitting naked in the prison’s kitchen sink.

One video uploaded from prison shows an inmate lining up to be punched by someone who the Daily Record believes to be John Reid, who was jailed in 2010 after inadvertently killing a man with one punch.

In social media posts, they brag about how easy it was to get online.

A spokesperson for the Scottish Prison Service said: “The possession of a mobile phone in prison is a criminal offence. If we receive information to suggest that prisoners are in possession of such devices, we will take all appropriate action and report it to the relevant authorities.”