TVNZ, citing strong public interest, wanted to publish photos showing the balloon hitting the power lines, catching fire and crashing, but not showing bodies.
Their request has the support of at least one family involved in the tragedy, the Still family, who lost daughter Alexis Still.
They want the photos to serve as a warning to others.
Mr Walker said he believes non-publication protects the families.
"If people want balloons catching fire, there's plenty of it out there," he said. "If it was me ... I wouldn't want pictures of me dying out there."
Mr Walker said as the tragedy unfolded he made a conscious decision.
"I'm a photographer, these are going to be valuable for investigating [the crash].
It was also a principle of copyright, he said.
"I could have made money on the day, a lot of money, from all around the world."
He said he got advice from other professionals.
"It's ownership of what you do, what you create is yours.
"TV want to use them without paying ... once they are out in the world, copyright? Forget it. You've lost your ability to track them."
He said he would "certainly consider it" if all the families of the victims asked for the photos to be released.
He said the support on social media from the public and colleagues has been "amazing".
"I have been really stunned by the responses."
The family of Alexis Still told TV3 News on Monday they felt Mr Walker was "grandstanding" in his refusal and he had no right to speak for the families.
Mother Vivienne Still said it was so people would know what they were getting into when they got into a balloon.
Her husband Allan said the people of New Zealand had a right to see the photographs.
When asked what he thought of those comments, Mr Walker said he felt sorry for the family, but it was their opinion and they were entitled to it.