Police in Iran say only one of the two Belgian tourists kidnapped near Bam at the weekend has been released, the official Irna news agency has reported.
The two Belgians disappeared in south-east Iran
Col Mohammed Asna-Ashari said a woman had been "freed from the clutches of the hostage-takers", while efforts to rescue her husband continued.
The two have been named on Belgian TV as Carla, 36, and Stefaan, 28.
On Tuesday, the Belgian foreign ministry said that the tourists had been found and were in good health.
It said Stefaan's mother had been in touch with him. The ministry did not confirm the two had been kidnapped.
"The woman tourist, named Carla, was freed from the clutches of the hostage-takers yesterday thanks to the efforts of the Noble Prophet Operational Base," Col Asna-Ashari, one of the base's deputy commanders, told Irna.
"Efforts for releasing her husband continue."
On Monday, another Iranian official said the Belgians had been abducted by a "well-known bandit" near the town of Fahraj, while travelling from Bam to Zahedan.
Esma'il Shah-Bakhshi demanded his jailed brother be freed in return for the tourists' release, the official added.
Armed drug smugglers have clashed frequently with Iranian security forces in the area.