Israeli Prime Minister Benjamin Netantyahu's personal lawyer, the former head of the Israeli Navy and four others are being probed by Israeli police in a fraud case.

Israeli police on Tuesday detained the former head of the Israeli Navy, Vice Adm. Eliezer "Chiney" Marom, over his role in Israel's so-called "Submarine Affair," and questioned him at the police's anti-fraud unit. Marom was being held on the suspicion that money that originated as bribes was transferred into his account. His personal bank accounts have been frozen by police until further notice.

"The Submarine Affair," or "Case 3000" deals with the alleged corruption probe regarding the Israeli government's purchase of three submarines from the German ThyssenKrupp company. The multimillion-dollar submarine deal with German shipbuilder ThyssenKrupp is the focus of a police investigation, which is looking into possible wrongdoing by Netanyahu's personal lawyer, David Shimron, and ThyssenKrupp's local representative.

Late Monday, a judge extended the custody of three other suspects in the affair, including Michael Ganor, a defense official-turned-businessman who represented the German company ThyssenKrupp in the multimillion-dollar deal, and Avriel Bar-Yosef, a deputy Israeli national security council head who played a key role in formulating the professional opinion supporting the deal. Ronen Shemer, a lawyer who works with Ganor, also will remain in custody.

Police also are investigating allegations against Shimron, who allegedly lobbied defense officials on behalf of ThyssenKrupp for the submarine sale, as well as the sale of military ships needed to defend Israel's off-shore gas reserves. He is under house arrest until Thursday.

Attorney General Avichai Mandelblit in Feburary authorized a full-blown criminal investigation into the submarine affair, stating that police had gathered enough evidence to raise suspicions “that some of those involved in the affair committed crimes of public corruption.”

Former Defense Minister Moshe Yaalon has threatened "to go public" if "Case 3000" does not produce an indictment. He has said publicly that while in office he put the brakes on the planned purchase of the submarines. But after Yaalon resigned in May 2016, Netanyahu renewed the negotiations.

Netanyahu is currently not suspected of any crime in relation to the affair. Netanyahu's office has repeatedly denied all allegations, and said the purchases were conducted in accordance with the recommendations of the Navy and Defense ministries.