WATCH: Organizer of George W. Bush inauguration reveals what's fishy about Trump's event

An investigation is underway into President Donald Trump's inauguration spending by federal prosecutors in Manhattan.

On Thursday, CNN's John Berman sat down with Greg Jenkins, who led George W. Bush's second inauguration.

Trump's inaugural committee raised a record-breaking $107 million from donors, however, he spent way less on the event than past administrations. This gap has left several people to wonder where all the money actually went.

"It's about double what then-president George Bush raised for his second inauguration. You had a smaller staff and more events. What do you make about the Trump amount?" Berman asked.

"I can't figure it out. They actually raised more than twice the amount that we raised. I think adjusted for current dollars, the amount we raised comes out to be about $54 million, which is quite a bit less. The two biggest costs are the events and staff. We had three times as many staff and four times as many events. So where that money went, I couldn't tell you," Jenkins said.

He added, "Most of the money came from donors. If I were a donor, I would like to know where that money went. I can't explain it."

Watch the full interview below via CNN.