An inmate at the Nassau County Jail has died, an official says.

The president of the Nassau Correction Officers Union says the inmate was not conscious when he was found in his cell just after midnight Wednesday.

The man was later pronounced dead at the hospital.

The cause of the inmate's death is unclear.

News 12 is told Nassau County police and the state Attorney General's Office are investigating.

News 12 reached out to the county for further details and have not heard back.