(CNN) -- Former New England Patriots star Aaron Hernandez was involved in an "altercation with another inmate" at the Bristol County House of Correction and Jail in Massachusetts, a county sheriff's department spokesman said Wednesday.
Hernandez, 24, who is being held on first-degree murder and weapons charges in the shooting death last year of his friend Odin Lloyd, had the altercation with an unidentified inmate Tuesday, said Bernie Sullivan, a spokesman for the Bristol County Sheriff's Office.
Neither man was seriously injured. Sullivan said the incident was under investigation.
Bristol County Sheriff Thomas Hodgson told CNN that jail officials will be looking at how the two came into contact because "no more than one inmate is supposed to be out at a time" in the unit where Hernandez is housed.
Hernandez's lawyer could not be reached for comment.
Hernandez has pleaded not guilty to the murder charge.
Authorities have said that Hernandez and two other men picked up Lloyd from his Boston apartment in a rental car shortly before he was found shot to death on June 17.
Surveillance cameras then captured the rental car leaving the crime scene and Hernandez carrying a gun as he returned to his home minutes later, according to authorities.
CNN's Susan Candiotti contributed to this report.