They include accusations of human trafficking, torture, murder and rape.
The Libyan attorney general’s office said the network included members of the security services, migrant detention camp leaders, and officials from African embassies in Libya.
Libya has been in turmoil since the fall of Muammar Gaddafi in 2011.
Power is dispersed between different militias and two rival governments, allowing illegal activities to thrive.
The country has become a key point on the route of hundreds of thousands of sub-Saharan African migrants trying to reach Europe by sea.
The investigations into smuggling networks are being carried out in conjunction with the Italian prosecutor’s office after a joint unit – pooling intelligence, coastguard and justice resources – was set up last year by the two countries.
The director of the attorney general’s investigations office, Seddik al-Sour, said many immigration department officials had been found to be involved
“There are 205 warrants against the persons who organised the illegal immigration and the human trafficking, and the torture, the killing and the rapes,” he told reporters.
His office had detected a direct link between smugglers and the Islamic State group, he added.