The bodies were discovered by a truck driver travelling through the desert and were recovered on Tuesday about 320 km southwest of Kufra and 120 km from the border with Chad.
"The driver got lost ... and we believe the group died in the desert about 14 days ago since the last call on a mobile phone there was on June 13," Kufra ambulance chief Ibrahim Belhasan said by phone.
Two of the bodies were Libyans and the others were believed to be migrants from Chad crossing illegally into Libya, Belhasan said.
Libya has become a major launching point for migrants seeking to reach Europe via the dangerous route across the desert and over the Mediterranean.
However, despite the conflict, its oil-based economy is also a draw for migrants seeking work.