Updated

Boston, MA (SportsNetwork.com) - Former NFL tight end Aaron Hernandez was involved in an altercation with another inmate Tuesday inside the corrections facility where he's being held.

"There was an altercation that took place in the unit where he's housed and he was involved in this altercation with another other inmate," Bristol County Sheriff Thomas M. Hodgson told WHDH in Boston.

Hernandez is kept segregated from the general population because of the high- profile nature of his case and Hodgson didn't say how he came in contact with another inmate.

"The standard operating procedure of a special management unit is that only one inmate is out at time," Hodgson said. "So we have to look at what if anything took place that would involve a failure on our part in procedure."

TMZ.com was first to report the altercation. Sources told the gossip website that Hernandez was taking a walk in a hallway when the altercation took place.

Hernandez pleaded not guilty in September to a charge of first-degree murder and five accompanying weapons charges in the shooting death of 27-year-old Odin Lloyd, a semi-pro football player who was dating the sister of Hernandez's fiancee.

Four others have been charged in the case, including Hernandez's fiancee and cousin.