Ownership of some of Boston’s highest-end condos hangs in the balance as part of a $3.5 billion legal battle stemming from a power struggle in the Saudi Arabian royal family.

A lawsuit claims that the luxury units were fraudulently acquired for $29 million as part of nearly $3.5 billion in disputed assets from 2008 to 2017 by Sakab Saudi Holding Co., which was controlled by the former Crown Prince Muhammed bin Nayef. The current ruler, Crown Prince Mohammed bin Salman, ousted bin Nayef in a 2017 purge and ordered the Sakab assets to be transferred to the Saudi Public Investment Fund.

Lawyers for the defendants deny the allegations of fraud against Sakab, which was created in 2008 to partner with the U.S. government on anti-terrorism and national security. They characterize the lawsuit as part of a campaign by bin Salman to quash rivals and silence critics. Universal Hub first reported the lawsuit.

“Plaintiff’s claims represent a stark effort by a foreign sovereign to reach into the United States to target a perceived dissident and political opponent by attaching property,” attorneys R. Robert Popeo and Scott C. Ford of law firm Mintz wrote in a court filing.

The disputed Massachusetts properties listed in the complaint include:

• United W10-C at the Mandarin Oriental, acquired for $4.3 million;
• United 5203 at One Dalton, acquired for $4 million;
• Unit 5202 at One Dalton, acquired for $9.75 million;
• Five units including a penthouse at Millennium Place in Downtown Crossing.

The complaint, originally filed in Suffolk Superior Court, claims that Sakab’s previous leadership used a variety of fraudulent schemes to acquire real estate across the globe, including off-the-book transactions. It seeks disgorgement of rents being paid by tenants – up to $20,000 a month, at a One Dalton unit – and for the properties to be placed in constructive trust pending the outcome of the lawsuit.

Attorneys for the defendants argued that the Sakab activities were lawful.

“What plaintiff describes in the complaint as defendants’ `fraudulent activity’ refers to conduct undertaken at the direction of the then-leadership of the Kingdom of Saudi Arabia, at times in partnership with the United States,” a court motion states.

The complaint has been transferred to the U.S. District of Massachusetts. It seeks to enforce an Ontario court’s ruling that the Massachusetts properties be placed in receivership.