The GOP strategist defended Trump's sons' involvement in the transition process and the family's business in an interview with CNN's Kate Bolduan.
"Conflicts of interest arise when you're sneaky about it, when you're shady about it. If you tell everyone, here's what's going on, here's the process, here's the people who are playing a role, that's being transparent," he said.
Spicer went on to cite the use of a camera by the elevator banks in Trump Tower as proof Trump's team was being transparent.
"What we've seen in government for so often is that people have been shady -- about their roles, hiding things, not releasing things. We have a camera for goodness sake. Every single person who enters Trump Tower, you get to see them go up, go down, they talk to the press."
"When is it enough? At some point, the level of transparency has exceeded any modern president in terms of who's involved," Spicer continued.
"No, that's not true," Bolduan replied. "There's a level of transparency when it relates to his businesses. Why there are so many questions is because we have not seen his tax returns, and I know we never will. But don't claim he is the most transparent president of all time."
Spicer said he was not referring to the President-elect but the transition process.
A Trump transition source told CNN Wednesday that Spicer is a leading candidate to be White House press secretary.
In a series of tweets, Trump announced his sons, Eric and Donald Trump Jr., will manage the President-elect's businesses while he serves as president. CNN learned that both of Trump's sons have played key roles in the transition process, with Donald Jr. vetting Trump's interior secretary pick, and Eric Trump being present for at least one of the meetings between Donald Trump and Mitt Romney.
A news conference originally scheduled for later this month to address how Trump would separate his business from his presidency was postponed until January.
CNN's Jim Acosta contributed to this report