Venezuelan authorities have confirmed that two high-ranking officers at a jail near Caracas have been arrested on suspicion of arms and drugs-smuggling.
The men, along with a National Guard captain, are accused of smuggling weapons into El Rodeo prison.
Twenty people died when rioting broke out in the prison earlier this month, leading to an ongoing stand-off between prisoners and security forces.
Armed inmates are holding some 1,000 other prisoners hostage, officials say.
Prosecutors said the men being held are Luis Rafael Aranguren, the governor of El Rodeo II, one wing in the prison complex, and the deputy governor of El Rodeo I, Ruben Jose Gonzalez Heredia.
Authorities also arrested Capt Jose Camargo Gomez.
They are suspected of belonging to a ring that smuggled weapons into the prison.
Rioting erupted in El Rodeo prison in Guatire on 12 June. There has been a tense stand-off since it was quelled on 17 June.
Several days later, troops took control of most of the complex and many of the inmates were transferred to other jails.
But a stand-off continues in one section of the prison and there have been sporadic gun battles.
One soldier and two prisoners have been killed in the violence, authorities say.
Officials say they remain open to dialogue, but that order must be restored.
Venezuela's overcrowded prisons see frequent riots between rival gangs.
The prison system, built to hold about 14,500 inmates, is currently estimated to house some 46,000 prisoners, according to the Venezuelan Prisons Observatory, which monitors prison conditions.