“A woman was arrested on suspicion of misconduct in public office on June 28. She has been taken into police custody.
“Enquiries continue. We remain in close contact with the Ministry of Justice.”
In May, a watchdog called for Wandsworth Prison to be placed under emergency measures amid concerns over security failings and issues with overcrowding, drugs, violence and self-harm.
A Prison Service spokesperson said: “Staff corruption is not tolerated and the former prison officer allegedly featured in this video has been reported to the police. It would be inappropriate to comment further while they investigate.”
HMP Wandsworth previously hit national news last September following the alleged escape of terror suspect Daniel Khalife.
Ian Acheson, a former prison governor, told the Mail Online: “If this footage is authentic, and I’ve been assured it is, the problems confronting a likely new Labour administration go far beyond overcrowding.”
“This is a national law enforcement agency. The idea that recruits to it would even contemplate, let alone participate in, sex acts is a stunning indictment of the utter chaos inside this prison. It won’t be an isolated incident.
“The state is no longer in charge here. The security implications and corruption threat is obvious and as explicit as the flagrant acts. The widespread infiltration of illicit mobile phones will mean that this footage is seen by huge numbers of prisoners.”