Monaco will ask the French Football League and FIFA to step in after claiming that sought-after striker Kylian Mbappe has been tapped up.
The 18-year-old has been linked with a move away from Stade Louis II following an outstanding season with Leonardo Jardim's side.
Mbappe burst onto the scene in 2015 when he became the youngest-ever player to score in Ligue 1 – breaking a long-standing record held by Thierry Henry.
The France international helped fire Les Monegasques to a first league title since 1999/2000, registering 15 goals and eight assists in 29 outings.
His exploits attracted the attention of Europe's elite, with Real Madrid, Arsenal, Manchester City and Paris Saint-Germain linked to his prized signature.
But the French champions have hit out at Mbappe's suitors for making illegal approaches for the teenage star and want action to be taken against the offending parties.
"AS Monaco regretfully notice that great European football clubs made contact with Kylian Mbappe (and his entourage) without its authorisation," the Principality outfit said in a statement.
"AS Monaco want to remind to these clubs that such actions are contrary to the article 211 of the Administrative regulation of the French Football League (Ligue de Football Professionnel) and to the article 18.3 of the Regulation of the Status and the Transfer of the Players of FIFA.
"To put an end to this unacceptable situation, AS Monaco consider asking the French Football League (Ligue de Football Professionnel) and the FIFA to commit disciplinary procedures against offending clubs."