Olchark Prison was constructed by Imperial slave labor, and was intended as a holding facility for political dissidents and hostages during the pacification of the Outer Rim Soncius Sector. However, since it was the first facility completed and its capacity was dreadfully overestimated, it was very shortly over capacity and understaffed. Prisoners came to Olchark from fifty worlds in a dozen sectors. It could probably have held two hundred prisoners safely. It was asked to hold over a thousand. Holding bunkers external to the main force dome were quickly constructed, but potable water and food were scarce under even the best of conditions.
Approximately two months before the Battle of Yavin, Alliance High Command learned the location of Olchark and attempted to gain access to the system. Because of the difficult and constantly changing hyperspace routes to and from the system, eventually the Special Forces operatives who guided the refugee ship gave up and hijacked an Imperial freighter leaving the system after a resupply, obtaining information about the secret probes transmitting encrypted information regarding nebular and stellar conditions in the area. Although this alerted the facility to the impending attack, the guards were stretched so thin that they could not mount even a remotely adequate defense.
The beings who wished to fight with the Rebellion were taken into training and those that could not or did not wish to were transshiped with the refugee ship to a safeworld far away, one with perhaps equally harsh conditions but at which, fortunately, they were free. Actual criminals were left in the custody of the Imperials, with conditions much improved by the significantly lessenned prison population.
Imperial records are scanty regarding the eventual fate of the facility. The warden in charge was executed after the raid, his superior, who exercised virtually no oversight, was politically connected and was merely demoted to a bureaucrat's position deep in the bowels of some Coruscant datacenter. Although it is certain that the facility remained open, it is not clear who sent prisoners, or indeed, resupply there.
New Republic Security reports indicate that "Olchark" is often used as a threat at Genorgah the Hutt's court, as a means of keeping recalcitrant debtors, operatives of limited loyalty, and small-time rivals from deviating from Genorgah's wishes.
Olchark Prison is in the Hluo-Ceti system on the fourth planet, which has a thin but breathable atmosphere for most species. It is naturally inhabited by two lifeforms - a persistent fungus and an invertebrate which feeds on it and whose excretions feed the fungus. The invertebrate's biology is such that ingesting it is a euphoric and hallucinogen. The creature was considered as an in situ interrogation aid, but was never tested sufficiently for Imperial Intelligence to have confidence in using it. Since that time it has been termed the Silver Spiral by the drug dealers who have begun to sell it throughout the sector...