Nottingham Forest have reported Tottenham Hotspur to the Premier League for making an illegal approach to Morgan Gibbs-White – and have threatened to sue their rivals.
Incensed Forest officials claim Spurs tapped up the player – against the rules – ahead of what is set to be a £60m move.
The 25-year-old has a release clause which Spurs are thought to have triggered, but Forest are furious with their approach and have accused them of effectively tapping up the player.
Mail Sport understands Forest have now told Tottenham not to make any further contact with Gibbs-White and have written to both Spurs and the Premier League.
Premier League officials are now likely to decide whether to investigate. Should they do so, and should Spurs be found guilty, they could face a hefty fine or even a transfer ban.
While Forest declined to comment, it is thought they attempted to resolve the situation amicably, but have not been able to do so. As a result, an explosive letter has been sent to Tottenham and the Premier League. They have also raised the prospect of legal action.
The midfielder has four England caps and had been of interest to Manchester City this summer.
He scored seven goals and notched up eight assists in 34 Premier League matches as Forest ended the season in seventh.
Spurs appear to be on a spending spree under new manager Thomas Frank, having already signed Mohammed Kudus for £55m.
Forest paid Wolves a club-record £25m plus add-ons in 2022 on a five-year deal. A crowd favourite, he has made 118 appearances for the club, and has scored 18 goals.
His last Three Lions action came in the 3-1 defeat by Senegal at the City Ground, where he came off the bench.
Tottenham declined to comment. The Premier League have been contacted for comment.
Release clauses have proven to be a controversial issue in the Premier League in recent years. Two years ago Chelsea were understood to have submitted an offer that activated a complex release clause, understood to be in the region of £35m, in Michael Olise's contract at Crystal Palace.
However, Chelsea's interest in the winger has aggravated Palace officials, who believed the Stamford Bridge club have crossed the line in their conduct during their attempts to sign the player.
Olise later signed a new contract and ultimately moved to Bayern Munich for £52m the following summer.
Forest are busy making progress in this summer's transfer market and are primed to make an opening bid for Manchester City forward James McAtee in light of Tottenham's Gibbs-White interest.
Forest have also lodged a bid for Brentford's Yoane Wissa but well below his valuation. Forest have already checked on McAtee's availability and are due to offer around £25m. Borusisa Dortmund and Eintracht Frankfurt also remain in the race for the midfielder.