Kevin Jonas lost "almost all" of his fortune when the Jonas Brothers were on hiatus.

The 37-year-old singer - who began his career in 2005 - admitted he has gone through highs and lows with his finances, and things were particularly bad when the Sucker hitmakers were on a break from 2012 to 2019.

Speaking to Lewis Howes on The School of Greatness podcast, he said: "I've seen the beginning of the success to financial success -- not knowing what money really was and understanding it -- to not having [it], to losing almost all of it."

Kevin attributed the lost of his wealth to a number of "bad business deals" that took place around "nine years ago."

Lewis asked: "You almost lost all your money?"

His guest clarified: "Yeah, most of it, like, down to the one 10 percent left."

Kevin explained he had "invested in a bunch of property" but "sadly" it just "wasn't the right partnership."

However, the Camp Rock star - who has daughters Angelina, 10, and Valentina, eight, with wife Danielle - suggested he couldn't speak about the situation for legal reasons.

He said: "I can't really get too much into it."

During the group's hiatus, Kevin formed a residential development company, JonasWerner, which built custom mansions within a commuting distance of Manhattan, invested in a food app called Yood and partnered with a new tech venture, We Hear It.

The Jonas Brothers, which also includes Kevin's younger siblings, Joe, 35, and Nick, 32, reformed in 2019 and Kevin has learned a lot from the difficult times.

He said: "I learned this lesson -- never wanted to learn it, but I did.

"But then, at the same time, reevaluated how to approach life and -- from that perspective, and look into the future. At the same time, I was able to really feel honoured that we could have a second shot at it."

Kevin's brothers were also on the podcast, and Joe admittted he and his siblings needed to learn to "trust" one another again before the group could get back together.

He said: "We all had to go figure out creatively what we could do on our own. We call it a break-up, but we had no intent of getting back together.

"There was too much under the rug to roll up … We had to trust each other a bit more with being, like, 'Actually, you are good in this band. You are talented. All of us and for different reasons.'"

Ultimately, he realised: "We can all share the spotlight, we could all share the studio, and we could all share songwriting, and we could all share money."