Rap star Diddy's American Express card number was posted online, TMZ reported Wednesday.

"Someone who clearly has a beef with Diddy" posted the account number for his "super exclusive" Amex Black card, along with his passport and private phone numbers, the article said.

A Diddy representative did not have a comment for TMZ, which said "sources close to Diddy" confirm the celebrity is aware of the incident and has "launched an internal investigation" into who exposed his card number.