An investigation has been launched into the death of Glenn Foster Jr., former defensive end for the New Orleans Saints, who died after being taken into custody in Alabama.

Foster, 31, died on Monday, the Pickens County coroner confirmed to NBC News on Tuesday. A cause of death has not yet been determined.

Glenn Foster (AP)

Inmate records show Foster was initially taken into custody in the Pickens County Jail on Saturday in connection to three counts of reckless endangerment, as well as a count each of attempting to elude police and resisting arrest.

Inmate records show he was released in that case at 3:14 p.m. Sunday, only to be rebooked at 3:16 p.m. on charges of simple assault and robbery in the third degree.

It's unclear why Foster was released and rebooked within two minutes, according to the records. There are no records indicating he was released after being rebooked.

Pickens County Sheriff Todd Hall referred questions on the matter to the Alabama State Bureau of Investigations, which he said was handling the case.

The Alabama Law Enforcement Agency, home to the bureau of investigations, confirmed that Foster was in custody at the time of his death. The agency also said that Foster's body had been moved to the state's forensic department as part of the inquiry.

"Nothing further is available as the investigation is ongoing," the agency said. "Once complete, the findings will be turned over to the Tuscaloosa County District Attorney’s Office."

Foster was a Chicago native who joined the University of Illinois football team as a redshirted freshman in 2008. He joined the New Orleans Saints as a defensive end in 2013 as an unsigned free agent, playing with them until 2014.

He and his wife, Pamela, started Southern Louisiana Granite following his departure from the NFL. He recently spoke to inRegister, a lifestyle magazine based in Baton Rouge, about how they expanded past granite countertop installation to more extensive remodel options.

"I’m a doer — I get things done,” Foster told the magazine in October. “I have a mindset where I could be anything I want to be in the world, and if my heart and mind are invested in it, I’ll be the best at whatever that is.”