Hilmi Balci, one of the four Anadolu Agency employees detained, has been released, Anadolu Agency's director-general said.
Facing an outpour of international condemnation, Egypt accused the four detained staff members of Turkey's Anadolu Agency of spreading "false news" and working with the Muslim Brotherhood, a group outlawed by Egyptian authorities.
Police raided their Cairo office on Tuesday and formally arrested them on Wednesday at a time of rising tensions between the rival nations.
Hilmi Balci, one of the four Anadolu Agency employees detained, has been released, Anadolu Agency's director general said.
The United States, an ally of both Turkey and Egypt, said it had seen news reports on the raid and arrests.
"If true, we call on the Egyptian government to release the detained journalists and allow for a free and open press in Egypt," a State Department spokesperson said.
The German foreign office criticised Egypt over the arrests.
“The German Foreign Office is concerned over the search of Turkish news agency Anadolu’s Cairo office and the arrest of four employees,” a foreign ministry spokesperson said.
“We have often expressed our worries about the situation of press freedom in Egypt. We believe that a free and diverse press is extremely important for a functioning social system.
New York-based rights group Committee to Protect Journalists slammed the arrests, saying " journalists operating in Egypt should not have to work in fear that they will be used to settle political scores between countries."
"Authorities must immediately release the Anadolu News Agency staffers arrested yesterday and stop using false news charges to harass and silence the media," CPJ added.
Journalists from Pakistan and Azerbaijan also slammed the Cairo raids.
The Egyptian Interior Ministry charged that the news bureau was a front for a "Turkish troll farm ... intent on broadcasting false news about the country's political, economic, security and rights situation."
It published the full names of those arrested — three Egyptian journalists and one Turkish citizen who handled the office's finances.
The ministry said the employees were working "with the aim of distorting the image" of Egypt and said their cases had been referred to the prosecution.
Turkey has summoned Egypt's charge d'affaires to protest the raid.
Details of the raid
Anadolu Agency's Director-General Senol Kazanci described on Thursday the raid and the following coverage in local Egyptian media.
Kazanci said the incident took place on January 14 around 1500-1600 GMT.
"A group of police wearing official uniforms came to our Cairo Office via minibus. There were our five staff members at the office," he said.
The bureau informed the AA headquarters in Ankara half an hour after the incident, he said they later contacted Foreign Minister Mevlut Cavusoglu.
"At midnight, police released one of the staff members, a woman, but four others were taken to a location we still don't know," he said.
Kazanci said the agency was not able to contact Egyptian authorities at that point and was not able to confirm the incident even took place.
The Turkish and Egyptian governments are fierce rivals since Ankara strongly supported Mohamed Morsi's administration, which was overthrown by a military ouster in 2013.
Ankara and Cairo are also on opposing sides of the Libyan conflict.
Turkey supports the UN-recognised government in Tripoli, which is under siege from forces loyal to eastern-based warlord Khalifa Haftar, who is supported by Egypt and the United Arab Emirates.