Liverpool Football Club has launched an investigation into how a star player's payslip - showing a monthly salary of £139,634 - ended up on the internet.
The document shows Norwegian John Arne Riise's net pay, his home address, national insurance number and other personal details.
The payslip - an ordinary payslip that even has a column for student loan contributions - has appeared on a series of football fans' forums.
A Liverpool spokesman said: "We are taking the matter extremely seriously and we are investigating."
Riise, 27, receives a basic salary of £120,000 and his April payslip reveals he was paid £4,000 in appearance bonuses and a £250 "points bonus".
The Kop ace also landed a Champions League salary increase of £15,384.
His take home pay was £82,413 and his monthly tax payment was £55,508. Bizarrely, £65 was deducted for meals.
Several Liverpool players' homes have been broken into during the last 18 months but Riise's home was not burgled.
A club insider said it is unknown how someone obtained the payslip.
He said: "It must have been stolen but the player simply doesn't know how it has happened.
"I can assure you that John Arne Riise is not in the habit of throwing payslips out. It's clearly been stolen and taken without his permission."