An investigation has been initiated after a video surfaced showing a female prison guard allegedly engaging in sexual activities with an inmate.

The video, purportedly taken inside HMP Wandsworth, shows a woman in uniform engaging with an inmate.

The video starts with the woman performing a sexual act on an inmate whose identity remains undisclosed.

It escalates to show the guard having sexual intercourse with the inmate while another prisoner records the act on his mobile phone.

The video also captures a glimpse of the cell, which includes a television and numerous piles of clothes strewn across a bunk bed.

During the recording, the prisoner filming remarks, "Guys, we've made history, this is what I'm telling you," while he smokes.

During the incident, the prison guard's radio, left on a side table, is heard crackling in the background with her colleagues communicating, oblivious to the events unfolding in the cell.

At one point, someone attempts to enter the cell, but the inmate recording the scene tells the person at the door to "give me a minute, one second," effectively stopping them.

Nevertheless, the prisoner recording the action instructs his friend to keep going with the guard, remarking: "This is how we live in Wandsworth."

The footage quickly spread across social media, prompting a police investigation.

A spokesperson for the Prison Service stated, "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."

A Met Police spokesperson informed, "A police investigation was launched on 28 June after officers were made aware of a video allegedly filmed inside HMP Wandsworth."

"A woman was arrested on suspicion of misconduct in public office on 28 June. She has been taken into police custody. Enquiries continue. We remain in close contact with the Ministry of Justice."

Ian Acheson, a former prison governor, expressed serious concerns about security in prisons based on the footage.

Speaking to MailOnline, he said: "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."