Their trial opened in the capital Bamako on Thursday in the run-up to a Jan. 1 deadline set by West African leaders for Mali to release the soldiers or face sanctions.
"The two minibuses carrying the 46 Ivorian soldiers have arrived at the Bamako appeals court. The hearing has resumed," the source said.
Forty-nine troops from Ivory Coast were detained after they arrived at Bamako airport on July 10. Three, all women, were later freed.
Those remaining, branded by Mali's junta as "mercenaries," were charged the following month with seeking to undermine state security.
Ivory Coast and the United Nations say the troops were flown in to provide routine backup security for the German contingent of the U.N. peacekeeping mission in Mali.
An Ivorian delegation travelled to Mali last week for talks on the crisis, and the Ivorian defense ministry said it was "on the way to being resolved."
Thursday's hearing was held behind closed doors and under heavy security, an AFP journalist said.
On Dec. 4, the Economic Community of West African States (ECOWAS) set New Year's Day as a deadline for the soldiers' release, failing which the bloc would impose new sanctions against Mali.