Amnesty International says the Syrian government's widespread and murky policies of disappearances have spawned a thriving market of bribery and exploitation.

Tens of thousands of people have vanished without a trace since 2011 and are believed to be in government detention. Often, family members do not even know if their relatives are still alive or where they're held.

Families pay brokers hundreds to tens of thousands of dollars for news of their disappeared relatives, sometimes only to receive false information in return.

The London-based rights group says that as the bribes trickle down to officials, they have become a steady source of income for the government.

Thursday's report by Amnesty also called on the world to enforce a 2014 U.N. Security Council resolution to end enforced disappearances in Syria.