The Centers for Disease Control and Prevention is investigating a botulism outbreak at the federal prison in Yazoo City after 17 inmates became ill from drinking homemade alcohol.

Last week, the inmates consumed alcohol they made in the prison, according to Mississippi Department of Health spokesperson Liz Sharlot.

The inmates then began showing signs of botulism and required hospitalization. They were transferred to three hospitals in the Jackson area and each received an anti-toxin, Sharlot said.

To date, 15 of the 17 inmates remain hospitalized, according to a press release issued by the Federal Bureau of Prisons. One inmate was transferred to a federal prison in Oklahoma City before he began showing signs of botulism. He was also hospitalized.

According to Sharlot, the inmates were hospitalized over the course of the week, with one hospitalized over the weekend.

The outbreak is the sixth botulism  in the United States prison system since 2004, Sharlot said.

Meanwhile, a Queensland father has been found guilty of killing his son and two friends — and seriously injuring a second son — by accidentally giving them a toxic home brew.

The jury delivered its verdict against William Neil Clarence Lynam after three hours of deliberation, finding him guilty of three counts of manslaughter and one of grievous bodily harm.

Lynam had pleaded not guilty to each of the four charges.