Five Premier League clubs, including Chelsea, could face a transfer ban and fines as they are currently under investigation by FIFA for operating against the rules when signing foreign players under 18 years old, reported the Telegraph on Wednesday.

"The proceedings are ongoing and, to date, no decision has been passed by the FIFA judicial bodies," said the world soccer governing body in a statement.

According to FIFA rules, no transfer of international player under 18 is allowed except for the following three cases: The player's parents move to the country where the club are located for non-soccer related reasons; the player comes from a country of the European Union (EU) or European Economic Area (EEA) and is no younger than 16 years old; the player lives within 50 kilometers from a national border and the club that want sign the player is also located within 50 kilometers from the same border.

According to French website Mediapart, Chelsea was caught with evidence in signing Bertrand Traore from Burkina Faso in West Africa. The Blues signed a professional contract with Traore in 2013 when he was 18-years-old and registered for him with the Football Association (FA) in 2014. However, Mediapart said that the young man played in total 25 games for Chelsea without registration.

Moreover, the contract between Chelsea and Traore was allegedly four and a half years while the maximum year of contract is three, required by FIFA.

Including Traore's contract, 14 of Chelsea's signings in the past three years are being investigated by FIFA. Mediapart said that the Blues could face at most two years of transfer ban, which are four transfer windows plus some 57,000 US dollars as fines.

Chelsea, in response, released a statement in which they denied any wrongdoing, saying that the club has been cooperating with FIFA and will not comment on any speculation related to confidential matters of players.