English Premier League club Chelsea has said it is cooperating with a FIFA investigation into possible violations of the global soccer governing body's rules regarding the signing of foreign players under the age of 18.

French investigative website Mediapart reported on Wednesday that FIFA's Integrity and Compliance unit would seek to impose a two-year transfer ban on the clubs as well as a fine of 500,000 Swiss francs (382,323 pounds).

Mediapart is one of several media outlets publishing documents obtained by Football Leaks.

The Football Leaks documents were obtained by German publication Der Spiegel and reviewed by Reuters in partnership with European Investigative Collaborations, a network of international media.

Chelsea said in a statement on Wednesday that "the club has fully cooperated with FIFA and has provided comprehensive evidence demonstrating its compliance with the applicable FIFA regulations".

FIFA's rules prohibit international transfers of players under the age of 18 unless their parents have emigrated for reasons unconnected to football or both player and club are based within 50 km of a national border.

Spanish clubs Real Madrid, Barcelona and Atletico Madrid have fallen foul of the rules in the past, with all three serving transfer bans for violations.

FIFA opened its investigation into the English clubs in September last year and said in a statement on Wednesday that it had not yet reached a decision.

"As communicated in September 2017, investigations were opened concerning Chelsea FC as well as other English clubs in relation to potential breaches of the regulations on the status and transfer of players," FIFA said.

British media, including the Daily Telegraph, the Guardian and the Times, reported that Chelsea broke transfer rules governing players under the age of 18 when they signed Burkina Faso forward Bertrand Traore in 2014.

The reports added that Chelsea were also under investigation for signing 14 under-18 players since the signing of Traore.

($1 = 1.0053 Swiss francs)