Centanni and New Zealander Wiig who work for the US broadcaster Fox News were seized by masked gunmen in Gaza City in August 14.
Ken Centanni told Aljazeera that the American was in Gaza to reflect the truth and had always respected the Palestinian people and their culture.
"I want his captors to know that Steve is an honourable man and always attempts to do what is right", he said.
"Steve will be more useful for the Palestinians if he is a free journalist rather than a hostage," he added.
No one has claimed responsibility for the kidnapping of the two journalists.
"We love Steve so much. His health, safety and life are your responsibility now," Centanni's brother said. "Please, contact our family, tell us that he is alive and has not been harmed."
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