Argentine club Velez Sarsfield has lodged a formal complaint with FIFA over Manchester City's signing of teenaged midfielder Benjamin Garre.
Velez said City tried to sign Garre from them when he was still a 15-year-old, which it alleges breached FIFA's rules on the transfer of minors.
FIFA has clamped down on the transfer of minors in the last few seasons with Spanish clubs Barcelona, Real Madrid and Atletico Madrid all hit by lengthy bans for breaching rules.
"Never have I experienced such an immoral act... We don't know what they offered the father and the child in order to convince them," Raul Gamez, Velez's president, was quoted as saying by the Daily Telegraph.
"In Velez, we defend values and we act in good faith. We are not interested in collecting 50,000 euros or 1,000,000 euros if said action is prohibited and may affect the player."
City denied any wrongdoing in their recruitment of the Argentine, who the English Premier League club says holds an Italian passport, allowing him to join Pep Guardiola's side on his 16th birthday, the report added.
(Reporting by Shravanth Vijayakumar in Bengaluru; editing by Sudipto Ganguly)