Mr Rayner said it was "impossible" for him to not be inspired by other images.
"Often I use my own photographs as reference but when sculpting clay figures or painting images on to ceramic plates it's usually necessary to use other photographs for reference.
"And sometimes inspiration even comes from other artworks - in a previous work I used a detail of Munch's The Scream and reworked it in rug wool using a completely different colour palette to the original. Though the finished work was clearly based on The Scream, there was no way it could be considered a copy."
Last week New Zealand Herald editor-in-chief Tim Murphy said he expected artists using the newspaper's work to ask for permission and consult on what they intended to use the work for.
"The photographer who captures an image such as this is a professional who deserves recognition - that should not be converted by an artist without reference to us," Mr Murphy said.
Mr Rayner said he had not personally been threatened with legal action.
However, the work has also been criticised by the family of Philip Nisbet, the husband she was convicted of murdering in May 2009.
