This incident is a serious and disappointing breach and those found responsible will be held to account. Ad Feedback Three of the jail's senior staff — prison director John Roper, who is on a final warning, security manager John Cooper and residential unit manager Doug Smith — have been on "special leave" since concerns about "security procedures" at the prison were raised in May last year. Footage of the pair getting hot under the collar has been shared on Facebook, with many speculating it was filmed at Antrim Grammar School in Co Antrim, Belfast. The clip, which has been shared widely, features what seems to be two teachers engaging in sex acts. The findings of the security review were referred to the police, who are investigating. Could not subscribe, try again laterInvalid Email Two teachers' alleged X-rated romp in a classroom was caught on camera - and a grammar school has been forced to deny any connection to it. The independent Corrections inspectorate would carry out its own investigation. Christchurch Men's Prison houses about inmates and is one of the country's largest prisons. I trust this clarifies the matter. Cellphones are contraband in prison. The incident took nine days to be flagged at a national level after local staff failed to report it. The school was forced to deny the video was filmed on premises in a statement sent out to parents Read More Ban mobiles in schools to improve grades and reduce bullying, says Culture Secretary "I would like to state categorically that the video was not filmed in Antrim Grammar School, does not feature any staff past or present from Antrim Grammar School, and indeed has absolutely no connection with the school whatsoever. A Corrections review found staff gave "favourable treatment" to some inmates who, according to leaked documents, were given cellphones during covert operations. The clip has been widely shared online Image: In April last year, Stuff reported Roper and Smith received employment warnings after an inmate at the prison self-harmed while left on his own for several hours in an exercise yard on June 21 last year. The prisoner had been charged with misconduct and his girlfriend was issued an exclusion notice, preventing her from visiting for six months. But the school has outright denied the claims in a message sent to parents this afternoon, Belfast Live reports.