Ман Сити, getty images
Representatives of FIFA confirmed to BBC Sport that now in relation to Man City and Chelsea, an investigation is being carried out regarding the fact that these clubs transfer players under 18 years.
Chelsea fell under suspicion for the third time. In 2009, the Blues received a ban on signing football players for 2 years, but subsequently won an appeal on this issue.
In May this year, the Premier League fined the City for 300 thousand pounds and also banned the signing of academy players for 2 years.
Both clubs deny any violations.
In January 2016, Real Madrid and Atletico received a ban on the registration of new players for 2 transfer windows. "Royal Club" subsequently managed to reduce the punishment by half, but Atletico served his sentence in full.