The bodies "have been prepared for the trip to their home country," a court official told AFP Wednesday on condition of anonymity, saying the investigating judge needed to authorize the order and submit it to the Argentine government.
Repatriation of the bodies of French university students Houria Moumni, 24, and Cassandre Bouvier, 29, was expected on Thursday or Friday, the official said.
Officers late Wednesday found clothing thought to be from one or both of the women, in the ongoing search for evidence in the area, a police source told AFP.
Two witnesses have told investigators they heard gunshots on July 16 in the part of the preserve where the bodies were found.
Moumni and Bouvier were apparently killed last week while hiking in the San Lorenzo Gorge.
Their bodies were found on Friday on a trail in an area overlooking the provincial capital of Salta.
One of the women was shot in the head and apparently sexually abused. The other was shot in the back.
Investigators have taken DNA evidence from the bodies, including hair samples thought to be of the culprit and, from one of the victims, traces of semen.
Police said Tuesday they had arrested a new suspect who has been linked to the murder weapon, identified as Daniel Vilte.
A man who rents horses to tourists in the area, 43-year-old Francisco Tejada, was arrested and later released for lack of evidence.