Qatari and Lebanese officials, who were mediating between Damascus and the rebels holding the nuns had said 150 women prisoners were released.
Syrian Information Minister Omran al-Zoubi insists only 25 prisoners were freed as part of the deal. He spoke today on state TV and did not say if the 25 were women.
His remarks were a rare acknowledgement by President Bashar Assad's government on its actions surrounding the internationally-brokered exchange.
The nuns were abducted by al-Qaida-linked Nusra Front rebel group in December.