A critically ill child and her mother were evacuated by the Armed Forces of Malta and brought to Malta on Sunday, according to a statement by the Italian Guardiacostiera.
The girl was found in a "serious state of dehydration" and needed urgent medical attention.
The Italian coastguard said on Monday that the mother and child two were among 28 asylum seekers on a boat in the Mediterranean.
They were rescued in recent days by a Liberian-flagged merchant ship off the eastern coast of Libya. The ship, which was sailing near the small boat adrift in the Mediterranean Sea, rescued all migrants and took them on board after it was instructed to do so by Italy's coast guard.
Another vessel, which is Italian-flagged, was also ordered to the area, after Italy's Coast Guard Operations Centre spotted the boat in clear distress while carrying out aerial surveillance.
According to Italy's coast guard, both the child and mother were urgently transported to Malta by a Maltese helicopter.
Malta's Armed Forces, which is tasked with migrant rescues and surveillance, made no mention of Sunday's incident, which only came to light on Monday evening through a Guardia Costiera press release.
When contacted, an AFM spokesperson demanded questions in writing. No reply had been received at the time of publication. On Tuesday, the spokesperson confirmed the evacuation had taken place.
The remaining migrants, who were about 80 miles off Syracuse, were transferred onto the Italian Coast Guard patrol boat CP 325 and brought to safety in Sicily's Pozzallo.
According to the Liberian ship that first rescued the group, there was no indication that anyone had died during the boat crossing.