A retired Boca Raton attorney is in a fight with his siblings over the family’s $100 million-plus real estate fortune, including assets in a frozen Morgan Stanley brokerage account.

Ronald N. Dubner’s attorneys say he spent decades helping his father, Harold, develop a vast real estate empire with office buildings, multi-tenant holdings and commercial shopping centers in Florida. But they say most of that wealth went to Dubner’s half-sister Leslie Strupp and the estate of his half-brother Bradley when their father died in 2004.