Donald Trump Jr. on Wednesday defended his father’s refusal to release his tax returns, arguing that there’s “a lot in a 12,000-page tax return” that shouldn’t be opened up to the public.

“We’ve been under audit for five years — who knows if that’s politically motivated or not — but our tax counsel, going through a 12,000-page tax return, has said they wouldn’t advise us to do it. It could create all sorts of other problems. I’m going to listen to them on that,” Donald Trump Jr. said on Salt Lake City radio station KSL, according to a clip highlighted by Buzzfeed News.

“When you have a business record, a business track record of my father, and 40 years of it, there’s a lot in a 12,000-page tax return that wouldn’t make sense to open up,” he added.

He also said that the campaign is trying to “keep the message on point.”

“We’ve seen how viral that craziness goes. We want to keep on point. We want to talk about the things that really matter to Americans and do that. When the people question ‘Well, does it show that your father’s not rich?’ Well, I don’t know. He put $65 million into a primary campaign that people said he had zero chance of winning,” Trump Jr. said. “I’d say he’s been pretty successful if he can do that. I don’t know a lot of people that would do that.”

Trump has repeatedly declined to release his tax returns, claiming that he cannot release them while he is under audit.