The EFL has launched a formal investigation into an alleged spying incident involving Southampton and Middlesbrough, just days before the two sides meet in the Championship play-offs. The controversy centers on a Southampton performance analyst who was reportedly caught filming Middlesbrough's training session and taking photos of tactics late Thursday morning.

The first leg of this high-stakes semi-final is set for Saturday at the Riverside Stadium, with the return match at St Mary's on Tuesday. According to BBC Sport, the Saints staff member was discovered on Middlesbrough's private property, ordered to delete the footage, and asked to leave the area. The Teesside club, understandably furious, promptly contacted the EFL.

The EFL released a statement Thursday evening confirming they have written to Southampton "requesting their observations" following Middlesbrough's complaint. The league is treating the matter as "potential misconduct under EFL regulations" and has declined further comment for now.

This isn't the first time such tactics have made headlines in English football. The EFL's current rules, which prohibit any club from "directly or indirectly observing another club's training session in the period of 72 hours prior to any match," were introduced seven years ago. That came after Leeds United were fined £200,000 for watching opponents train before matches. In that case, Leeds boss Marcelo Bielsa admitted to sending staff to scout every team they faced that season, a revelation that sparked widespread debate about the line between preparation and gamesmanship.

For Southampton and Middlesbrough, the stakes couldn't be higher. Both clubs are vying for promotion to the Premier League, and this off-field drama adds an extra layer of tension to an already intense playoff battle. As the investigation unfolds, fans will be watching closely to see how this story—and the matches themselves—play out.