Updated

A Mexican drug cartel has reportedly put a hefty price tag on the head of Maricopa County Sheriff Joe Arpaio.

As parts of Arizona's immigration law, SB 1070, went into effect last week, a Mexican drug cartel sent out text and audio messages offering rewards to anyone who would join its fight, a source who says his wife received the message told MyFoxPhoenix.com.

"It's offering a million dollars for Sheriff Joe Arpaio's head and offering a thousand dollars for anyone who wants to join the Mexican cartel," the man, who wants to remain anonymous, told the station.

The instructions included directions to pass the message along and listed an international phone number, MyFoxPhoenix.com reported.

The man reported the message to the Sheriff’s Department, which says it believes the message originated in Mexico and could be credible. But even if the message isn’t authentic, Lisa Allen of the Sheriff's office told MyFoxPhoenix.com, it could still pose a threat.

"It's going so many different places that our folks are looking at it and thinking well, at any given point in time, it could land in front of some crazy person who thinks I can do that," she said.

The sheriff's office hopes to track down the exact source of the messages, but says that may be difficult to do with an international number, the station reported.