Three senior naval officers have already been arrested in the probe and the announcement signalled a spreading corruption scandal that implicated members of the top echelons of the navy.
Vice Admiral Ted Branch, director of naval intelligence, and Rear Admiral Bruce Loveless, director of intelligence operations, were temporarily barred from viewing classified material based on allegations linked "with an ongoing Naval Criminal Investigative Service (NCIS) investigation" into illegal dealings with the chief of a defence contractor, Navy spokesman Admiral John Kirby said yesterday in a statement.
The two admirals faced allegations "that involve inappropriate conduct prior to their current assignments" and before their current rank, he said.
There was no indication either of the officers had breached classified information, he added.
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At the centre of the case is a Malaysian businessman, Leonard Francis, the CEO of Glenn Defence Marine Asia, who has been charged with conspiracy to commit bribery by US authorities.
Francis allegedly sought to secure multi-million dollar government contracts to provide food and supplies to US naval ships travelling through Asia, in exchange for bribes that included offers of prostitutes, luxury travel and other perks.
The case also raises fresh questions about how the Pentagon oversees numerous contracts, despite efforts to tighten oversight and prevent abuses.
The US Attorney's Office in San Diego first announced the case last month.