JERUSALEM — Two former close aides to Prime Minister Benjamin Netanyahu of Israel are among those facing likely criminal charges in one of the country’s biggest corruption scandals yet, arising from the multibillion-dollar purchase of submarines and missile boats from Germany.

A former chief of staff to Mr. Netanyahu, David Sharan, is accused of accepting bribes from an Israeli agent for the shipbuilder, ThyssenKrupp Marine Systems. David Shimron, who has served as a personal lawyer and close confidant to Mr. Netanyahu and is also his second cousin, is accused of laundering money to help the shipbuilder’s agent, Michael Ganor, conceal his role in a separate financial transaction .

The case is not related to last month’s indictment of Mr. Netanyahu on charges of bribery, fraud and breach of trust, but adds to the cloud lingering over him and his political future.

The charges against Mr. Netanyahu’s former aides are only tentative at this point. The two men — as well as the others facing the charges — are entitled to a hearing at which they can try to persuade prosecutors to drop or reduce the charges before an indictment is issued. They have all denied wrongdoing.