"Andrea" was called the facilitator for the godfathers of the Mexican Mafia. She told 10News, "I literally ran all the prisons. Donovan, San Diego Central Jail, I ran it. Vista, George Bailey …"

Multiple sources told 10News she was a trusted confidant of the highest-ranking members of the mafia.

"This carnale (slang for 'brother' in Spanish) has the keys. They call it the keys to L.A. The carnales have the keys to San Diego," Andrea said.

The carnales are the three top bosses south of Los Angeles. They run their criminal network with near impunity from behind bars.

"They run the prisons … that is how it works," she said.

The "uncle" often stays in the SHU, which is the secured housing unit and has the tightest security in prison. The facilitator delivered their orders to the outside world, whether it was about murder or money.

"A majority of the mafia money comes from sales in prison," said Andrea.

Generated by drugs or extortion, the Mexican Mafia -- or Eme -- also charges a tax to gang members behind bars and the gangs on San Diego streets.

"If they don't meet their quote, there would be hell to pay," said Andrea.

Andrea led a double life, as she was also an FBI informant. Her close relationship to the Mexican godfathers helped break a major case for the Violent Crimes Task Force led by the FBI.

"When they came and approached me, that is what they really wanted -- the dirty cops or guards," she said.

Andrea said some prison guards brought drugs into the prison.

"We pay them x amount of dollars, we give them heroin, we give them meth. They take it in for us, they give it to the inmate it's supposed to go to and it's distributed," she said.

There is tremendous profit in this, she added.

"A piece of crystal, about the size of a dime, goes for $200 in there. On the streets, you're lucky to get $10 for that," said Andrea.

Anyone else smuggling in drugs also must pay the mafia a tax, even a corrupt lawyer or greedy bail bondsman, she said.

"There are lawyers who work for us … He (the bondsman) has to give me a chunk of the drugs or give me 10 percent of what he made off of it," said Andrea.

The operation is well organized, with each part of the prison designated to a specific person to run. Communication among the members is not a problem.

"They have tried numerous times to get rid of the cell phones; they can't," said Andrea.

She also told 10News it's not just cell phones. Personal letters called kites are passed around, witch each holding secret instructions.

"There is a code to it. You have to know it," said Andrea.

In the letters, any reference to a Las Vegas steak dinner meant they wanted heroin brought into the prison or jail. A monthly car payment meant a section of Donovan owed $500 to the carnales. When there is a mention of a green light, Andrea said, "When we tell someone they have a green light, I am giving orders to go kill somebody."

Whenever a green light came out, she would tell the FBI. She said the FBI would then tell the potential target.

"The FBI did everything it could do so these people would not get hurt," she said.

The inside information paid off in a major enforcement operation last spring in which the Violent Crimes Task Force swept through San Diego neighborhoods and arrested several Mexican Mafia soldiers and indicted some of the top Mexican Mafia leadership in California's prisons. They also took down at least one law enforcement officer who worked for the mafia inside San Diego's downtown jail.

The informant and the FBI have now had a falling out. She said the FBI broke their promises to protect her, but the FBI said she was caught dealing drugs and is now in jail.

She is being held in seclusion to protect her.