The police are investigating after a video surfaced online appearing to show a female prison officer having sex with an inmate in a cell in Wandsworth Prison.
It is not known when the footage, which showed the officer in uniform, was taken.
A Prison Service spokesman 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.”
The Met Police said: “We have been made aware of a video allegedly filmed inside HMP Wandsworth.
“A police investigation is under way. At this early stage there have been no arrests. We are in close contact with the Ministry of Justice.”
The footage, shows the guard having sex with the prisoner while his cellmate films on a mobile phone, according to MailOnline which first reported the story.
The friend ,who is smoking while recording, reportedly says: “Guys we've made history, this is what I'm telling you” and “this is how we roll in Wandsworth.”
It comes two months after a watchdog called for the scandal-hit prison to be put into emergency measures amid concerns over failings in security and severe problems with overcrowding, drugs, violence and self-harm.
Chief inspector of prisons Charlie Taylor wrote to Justice Secretary Alex Chalk to issue an urgent notification for improvement at the category B Victorian jail in south-west London after “deeply concerning” inspection findings.
Mr Taylor – who previously suggested the jail should be closed – told Mr Chalk the prison was “still reeling” from a “very high-profile” alleged escape in September last year.
Daniel Khalife is accused of fleeing custody while being held on remand over spy charges. He allegedly strapped himself underneath a food delivery lorry and was arrested a few days later. The former soldier denies all the charges against him and is due to stand trial in October.
Security remained a “serious concern” at the prison, with “chaotic” wings and staff across most units unable to “accurately account for their prisoners during the working day”, Mr Taylor warned as he described it as “unfathomable” that bosses had “not focused their attention on this area”.
