The FBI had offered $2 million for information leading to Bulger's arrest of Bulger and $100,000 for information leading to Greig's arrest.
The agency said in a statement Friday that it paid the reward money to more than one individual. It did not identify them.
Authorities said previously that the tipster who lead them to Bulger was a woman who saw a television news report about a publicity campaign in the search for Bulger and Greig.
The couple have pleaded not guilty to multiple charges.