Francesco Lefebvre d’Ovidio, the brother of Silversea Cruises’ chairman and former owner, is suing Royal Caribbean Group for allegedly depriving him of shares of the luxury passenger shipping brand.

But Royal Caribbean is aiming to throw out the case, arguing that Francesco has no claim to the Silversea shares.

Manfredi Lefebvre d’Ovidio sold two-thirds of Silversea, which the brothers’ father Antonio Lefebvre d’Ovidio founded in 1994, to Royal Caribbean in June 2018 in exchange for paying $1bn of debt held by the then–Silversea parent Heritage Cruise Holding.

He sold the rest of the company to Royal Caribbean in July 2020 in exchange for 5.2m Royal Caribbean shares given to Heritage.

Francesco filed a lawsuit in a Miami-Dade County court in Florida on 23 May against Royal Caribbean for allegedly buying Silversea in July 2018 while rejecting what he argued was his entitlement to 52.1% of Silversea’s shares.

Francesco, who left Heritage Cruise two decades ago to become a history professor, based this Silversea claim on Manfredi’s refusal to give him the remaining 48% of family-owned Coimar in 2001 in exchange for 52% of Eurosecurities. Silversea’s original parent, Eurosecurities was dissolved in 2004.

Francesco filed a lawsuit against Manfredi in an Italian civil court in 2008, where a judge ruled that Manfredi had to return 52.1% of Silversea to him due to Manfredi’s 2001 refusal to give him 48% of Eurosecurities

The US lawsuit alleges that Manfredi tried to prevent his brother from getting his 52.1% share in Silversea by putting the cruise ship owner under various shell companies and then Heritage Cruise before selling it to Royal Caribbean.

Franceso’s Florida complaint then alleged that Manfredi repeatedly told Royal Caribbean that 52.1% of Silversea — worth €800m ($817m) — belonged to him, but the Miami-based cruise major nonetheless took full ownership of Silversea.

“Royal Caribbean thus knowingly acquired possession of property that Manfredi did not legally possess, has derived substantial revenues from that property to which Francesco is entitled, and has steadfastly rejected and refused to acknowledge Francesco’s entitlement to that property and the rights and benefits that flow from it,” Francesco’s lawyers said in the lawsuit.

Francesco is also still trying to acquire his purported stake in Silversea by pursuing 52.1% ownership of Manfredi-owned Heritage Group, which holds $1.3bn in assets across several sectors, in an Italian civil court.

That case has been adjourned to December.

Royal Caribbean moved Francesco’s Miami-Dade lawsuit to the US District Court for the Southern District of Florida in June and then filed a motion to dismiss the lawsuit on the basis that, among other things, Francesco never owned any part of Silversea.

“Francesco alleges that he has not even had indirect possession of any Silversea shares, through his former interest in Eurosecurities, since 2001,” Royal Caribbean’s lawyers wrote.

“Thus, pursuant to Francesco’s own allegations, Francesco would have been unable to confer that benefit on Royal Caribbean.”

Royal Caribbean, which declined to comment on the lawsuit, also alleged in its motion that Francesco failed to make a valid claim for unjust enrichment.