Kader Arif, junior minister for veterans at the Defense Ministry, initially confirmed the news but then backed away from his statement, saying his sources for the information were news media, Radio France Internationale reported.
Several media outlets reported Thursday the family -- a couple, their four children and an uncle -- was found in a house in Nigeria and had been freed. The husband worked for the French energy provider GDF Suez and the family lives in Yaounde, Cameroon's capital.
The family was kidnapped Tuesday from Waza National Park in northern Cameroon near the border with Nigeria. French officials said they believe the Nigerian separatist group Boko Haram carried out the kidnapping.
The French Foreign Ministry called Arif's announcement "astonishing" and said it could not confirm the report, RFI said. The president's office also said it could not confirm the report.
A Cameroonian military source told news agencies the hostages were freed, RFI said, but another Cameroonian minister denounced the story of the release as "a crazy rumor."