New York | Shortly after he left office, former president Donald Trump shared apparently classified information about US nuclear submarines with an Australian businessman during an evening of conversation at Mar-a-Lago, his private club and residence in Florida, according to two people familiar with the matter.

The businessperson, Anthony Pratt, a billionaire member of Mar-a-Lago who runs one of the world’s largest cardboard companies, went on to share the sensitive details about the submarines with several others, the people said, potentially endangering the US nuclear fleet.