Former President Donald Trump has repeatedly been accused of leaking US secrets, but the latest allegations against him involve key details about some of the most sensitive weapons in the US nuclear arsenal.

Trump gave key details on the US Navy’s elite submarine fleet – including the number of nuclear warheads they can carry and how close they can get to Russian vessels without being detected – to Australian billionaire Anthony Pratt, who passed the information on to dozens of friends and contacts, according to ABC News and The New York Times.

The alleged disclosure is only the latest in a string of cases that raise grave questions about Trump’s willingness to keep the nation’s secrets – an issue that’s only going to remain front and center given his commanding lead in the polls to secure the Republican nomination to challenge President Joe Biden again next year.

“Very few people in the US government know the exact configuration of the nuclear subs,” said Joe Cirincione, a security analyst who held the highest clearance level when he worked in Congress on nuclear weapons issues. If true, Trump’s disclosure gets to the heart of US capabilities, he said.