13 female corrections officers at a Maryland state prison are under investigation for allegedly helping a national gang shuttle drugs and money from jail.

The news surfaced Tuesday, when federal prosecutors indicted more than a dozen prison guards. They claimed that the officers gave control to the gang leaders, allowing them to engage in illegal activities right under the nose of the law.

The indictment detailed a strange situation, in which the officers of the jailhouse were in deep cahoots with their inmates.

According to the Washington Post, four corrections officers became pregnant by one inmate. Two of them had their inmate's first name, Tavon, tattooed on their neck and wrists.

The gang, named the Black Guerilla Family, was supposedly aided by the guards to run their shady dealings by smuggling in phones, pills and other forbidden materials stuffed in their underwear, hair and shoes.

One inmate even bought luxury cars from jail, including a Mercedez-Benz and BMW that he allowed some prison guards to drive.

"The inmates literally took over 'the asylum' and the detention centers became safe havens for BGF," FBI Special Agent in Charge Stephen E. Vogt said, with reference to the Black Guerilla Family gang.

The gang was first founded in California in the 1960s, but is now a widespread operation spanning the entire US. According to the Justice Department, the government became aware of the gang's existence in the 1990s once members began getting arrested. They are involved in narcotics trafficking, robbery, assault and homicides, and were a dominant gang in the Baltimore prison system by 2006.

The officers also reportedly informed inmates about upcoming cell searches. One guard told an inmate in a recorded phone call that officials were going to "pull a shakedown," that evening.

"Let me call all these dudes in my phone and let them know," she said.

State prison chief Gary Maynard regretted he didn't catch on to the thievery and law-breaking early on.

"It's totally on me," he said. "I don't make any excuses. We will move up the chain of command, and people will be held accountable."