A major hangar-leasing business at Long Beach Airport fired its longstanding CEO this month and then swiftly sued him, alleging he tried to walk away with company property to prop up his own competing business. The former CEO has denied the accusations, saying the situation is an unwinding of a complicated business relationship “that unfortunately went public.”

The Aeroplex/Aerolease Group is one of the largest managers of coveted hangar and office space at LGB, and for years, CEO Curt Castagna ran the business with the backing of the Widelitz and Arkin families, who control the company. Aeroplex/Aerolease Group also has a major stake in hangar and office property at the Van Nuys Airport.

After a decades-long relationship, the families are now in the messy process of trying to disentangle their company from Castagna, who is a nationally known player in the air travel industry — in part because of his prominent business advocacy roles with the National Air Transportation Association, Long Beach Airport Association and Van Nuys Airport Associations.

Aeroplex/Aerolease Group sent a press release Wednesday announcing Castagna’s firing and the lawsuit. Hours later, Castagna sent his own announcement, saying he’d “stepped away” from managing the company’s leases to focus on his own consulting company.

Castagna was once “almost like a member” of the families that own the Aeroplex/Aerolease Group, even officiating two weddings for the grandson and granddaughter of the company’s founder Milton Widelitz, according to court documents.

Now, though, the Widelitz and Arkin families are accusing Castagna of using their company for his own interests and refusing to give up control of what’s rightfully theirs after a dispute ended with him being terminated on May 6.

In a lawsuit filed May 15, lawyers for the Aeroplex/Aerolease Group say Castagna stole company records, locked down social media accounts, limited IT access and even refused to turn in his keys since being terminated.

The company’s owners and interim CEO have “had to spend a ridiculous amount of money” just to regain access to their building and hire an outside IT consultant to try to recover their data and regain control of their website and email systems, according to Stuart Pfeifer, a spokesman for the Aeroplex/Aerolease Group.

If not for employees who still have access to their tenant lists and other crucial systems, the company would be in a “worst-case scenario,” Pfeifer said.

Castagna, the lawsuit alleges, had been intertwining the Aeroplex/Aerolease Group’s resources with his own business venture to boost its prospects.

According to the lawsuit, family members got suspicious after finding out in 2015 that Castagna had started a consulting firm with a similar name to their company: Aeroplex Group Partners. But because they retained a minority stake in Aeroplex Group Partners and wanted to keep the well-connected Castagna happy, they didn’t press the issue too aggressively, the lawsuit says.

Castagna says his company, and the intertwining of operations, brought value to Aeroplex/Aerolease Group. But over the years, family members grew uncomfortable with how much time he was spending on Aeroplex Group Partners and how entangled the businesses became, according to the lawsuit.

A final straw came when the Aeroplex/Aerolease Group’s website and social media were “suddenly” rebranded to Aeroplex Group Partners, seemingly giving Castagna’s company credit for the family’s holdings, according to Pfeifer.

Since filing the lawsuit, lawyers for the Aeroplex/Aerolease Group have sought a judge’s order forcing Castagna to hand over access to the company’s systems, return company property and stop acting as if he’s employed by Aeroplex/Aerolease Group.

Castagna has fired back in court documents, saying anything he’s retained is the rightful property of his company.

One item of contention — a website at aeroplex.net — still prominently features a photo of Castagna and is branded with his company’s name, Aeroplex Group Partners.

If he were forced to hand the domain over to his former employer, Castagna says in a court filing, ​​it would cause “irreparable harm” to him and other third-party vendors featured on the site.

In a statement, Castagna said he looks forward to working with his former employer to “unwind long-standing business relationships in a manner that allows all parties to flourish in the future.”