The weekend-long lockdown at Lieber Correctional Institution ended Monday afternoon, but officials still won’t say just what prompted the extra security measure.

The lockdown at the maximum-security prison in Ridgeville began Friday, due to “an internal matter” that required investigation, S.C. Department of Corrections spokesman Clark Newsom said. Prison officials suspended the lockdown at 1 p.m. Monday without releasing additional details.

Rumors swirled among the families of prisoners, including tales of a riot and the arrest of a prominent prison official. Newsom said neither rumor was true but he was not at liberty to discuss specifics due to the ongoing investigation.

During a lockdown, the prison’s 1,400 inmates are confined to their cells around the clock. Visitation hours are cancelled, as are recreation time and showers. Prisoners are generally served cold, bagged lunches rather than warm meals, which generates a fair amount of grumbling.

This lockdown comes just a few months after a January riot at the prison. Inmates broke off metal desk legs and used them to assault two officers who were keeping watch over a dorm with 229 hard-core offenders.

The riot lasted five hours before a special response team shot tear gas into the building and recaptured the inmates.

In a recent interview, Lieber Warden Wayne McCabe said lockdowns are a necessary evil in the prison at times when word surfaces of possible threats.

One recent rumor concerned a gun that had supposedly been smuggled onto the prison yard. The rumor turned out to be false, but staff had no choice but to scour the grounds to ensure no danger existed, McCabe said.

“You can’t take these things for granted and assume somebody’s just playing because there may be some truth to it,” he said.