They were then flown to Libya’s Tripoli where they have been posted to frontline positions, said the report.
Another 1,350 men crossed into Turkey on January 5, the sources told The Guardian.
The fighters have signed six-month contracts directly with the GNA for $2,000 a month, sources said. All have been promised Turkish nationality, they added.
Turkey is also paying medical bills for injured soldiers and is responsible for repatriating the dead to Syria.
“This is a very different situation to Syria,” The Guardian quoted Claudia Gazzini, a senior Libya analyst with the International Crisis Group, as saying.
“Anti-Turkish sentiment is already strong because of Ankara’s intervention and could grow as a result of this.”