More than 16,000 migrants returned home from conflict-wracked Libya in 2018 under a "voluntary return" programme run by the International Organization for Migration, the agency said Wednesday.
"16,753 irregular migrants were able to return to their countries of origin last year," programme coordinator Jomaa Ben Hassan told AFP.
Many had risked their lives in failed bids to cross the Mediterranean to Europe, he said.
The migrants were from 32 countries in Africa and Asia, Ben Hassan added, saying the statistics did not include migrants whose cases were being handled by the UN's refugee agency UNHCR.
The refugee agency said in turn that 4,080 refugees and asylum seekers had been evacuated from Libya for resettlement - including some initially to transit countries -- between September 2017 and last month.
In a brief statement earlier this week, UNHCR said 56,000 refugees were waiting for their chance to leave Libya.
People traffickers have taken advantage of the chaos that followed the NATO-backed revolt that toppled and killed dictator Moamer Kadhafi, turning Libya into a major conduit for migrants seeking a better life in Europe.
Thousands of people have crossed Libya's southern border in recent years and travelled onwards to the Mediterranean coast, but they often face abuse and in some cases have been sold into slavery.
After being intercepted or saved at sea, migrants are often detained in inhumane conditions, at which point many opt for repatriation.
International organisations including UNHCR regularly denounce the mistreatment of migrants in Libya.