UNION - Union County's coroner says more tests are needed to determine how an inmate died at the county jail.

The Herald-Journal of Spartanburg reported that Coroner William Holcombe said he needs more information before he can determine how 34-year-old Robert Franklin Gregory of Union died.

Gregory was found unresponsive in a jail cell shortly before 5:30 a.m. Sunday.

Gregory had been jailed on a criminal domestic violence charge and was awaiting a bond hearing. Jail workers and paramedics were unable to revive Gregory.

Sheriff David Taylor said he could not talk about the investigation.

The State Law Enforcement Division is investigating.