Mediaworks didn't respond to requests for comment about the statement.
When contacted by the Herald last week, Max Key said he "wasn't doing media" and didn't want to comment.
But George FM DJ Aroha Harawira spoke out in support of Key, saying he should be judged on his musical ability and not his father's politics.
"I haven't met Max Key yet myself, I've never seen him DJ, but I heard him on George FM last night and I thought he played a pretty sweet set," Harawira wrote on her blog site.
"I value my friends' opinions and I'll give the guy a chance. I think you should too ... Say what you want about John Key, but leave his kids out of it."
Max Key's first show on George FM is on February 16, where he'll unveil his new single, Forget You, rumoured to be about his recent split from Amelia Finlayson.
In an interview on the station, Key said he'd been working on his material on his own, and he was "super excited" to release it. Co-host Jay Bulletproof said he had heard the song, and it was an "absolute banger".
"I'm proud to say I'm releasing my first single Forget You. Previewing on my first show on George fm nights, Tuesday the 16th at 10pm ... I can't wait to drop this," he wrote on Instagram.
- nzherald.co.nz