Southampton FC has been charged by the English Football League (EFL) with spying on Middlesbrough ahead of their Championship play-off semi-final. The club is alleged to have breached EFL Regulation 3.4, which requires clubs to act towards each other with the utmost good faith, and Regulation 127, which prohibits any club from observing or attempting to observe another club's training session within 72 hours of a scheduled match between the two clubs. The alleged incident occurred on Thursday morning, when a Southampton performance analyst was caught recording Middlesbrough's training session and taking pictures of their tactics. The analyst deleted the footage and left the area, but Middlesbrough were furious and contacted the EFL. The EFL has stated that Southampton will have 14 days to respond to the charges, but will ask the independent disciplinary commission to shorten the response period and list a hearing at the earliest opportunity. The first leg of the semi-final takes place at Riverside Stadium on Saturday, with the return at St Mary's on Tuesday. The EFL does not comment on active cases, but there appears to be no suggestion that Southampton could be thrown out of the play-offs. The rule against spying was brought in seven years ago after Leeds United were fined £200,000 by the EFL for watching opponents train before matches. A member of Leeds' staff was found acting suspiciously outside Derby's training ground on 10 January 2019, before a fixture between the two sides. Manager Marcelo Bielsa revealed he had sent a member of staff to watch training sessions of every team Leeds had played that season. The EFL found Leeds breached rules over treating teams with 'good faith'. The fine handed to Leeds provides precedent, but that came before the specific regulation existed.