Carlos Tevez, Juan Veron and Dirk Kuyt have been named by hackers Fancy Bears as three of the players permitted to use otherwise-banned medicines during the 2010 World Cup.
Tevez and Veron are two of five Argentinian players listed in a document which details therapeutic use exemptions (TUEs) and declarations of use of medicines for 25 players during the tournament in South Africa more than seven years ago.
The Fancy Bears have previously published details of TUEs - essentially a doctor's note permitting the use of an otherwise-banned substance to treat a medical condition - in Olympic sports.
And today's publication of hacked data was the Fancy Bears' first disclosure in football.
Tevez, who has played for Manchester United, Manchester City and West Ham, former Chelsea and United playmaker Veron and ex-United defender Gabriel Heinze all declared the use of Betamethasone, a corticosteroid with a variety of uses.
It does not feature directly on the World Anti-Doping Agency's prohibited list, but is banned dependent on the concentration detected, and is covered in section nine of the list. That reads: "All glucocorticoids are prohibited when administered by oral, intravenous, intramuscular or rectal routes."
Former Liverpool and Holland forward Kuyt was revealed to have used dexamethasone, apparently for pain relief due to dentistry issue with his root channel.
Mario Gomez was one of four Germany players listed. Gomez received a TUE for salbutamol, a common asthma medication.
Ex New Zealand, Blackburn and QPR defender Ryan Nelsen - listed as 'Nelson' on the published form - declared the use of prednisone, another corticosteroid.
No England players were listed and there is no suggestion of wrongdoing on the part of those named.