Two lawyers close to Israeli Prime Minister Benjamin Netanyahu were questioned Sunday over their roles in suspected corruption around the purchase of German submarines, media reports and police said.

Police said they had detained “two senior lawyers for questioning as part of the (submarine) affair,” refusing however to confirm their identity at this stage.

Israeli media identified both as being close to Netanyahu, naming one as David Shimron, a relative of Netanyahu and his family lawyer who also represented German industrial giant ThyssenKrupp in Israel.

The second person had not been named.

Last month, Germany signed a deal to sell three Dolphin submarines from ThyssenKrupp to the Israeli navy.

Negotiations on the sale had been frozen for three months due to concern in Berlin over the corruption investigation in Israel.

The investigation involves officials from the Israeli security establishment as well as people working locally for ThyssenKrupp.

Shimron has already been detained for questioning over the affair.

Netanyahu himself has not been named as a suspect in the submarine case.

He is however being investigated in two other separate graft probes, and Israel’s Channel 2 television said he is to be interrogated again upon his return from London, where he was wrapping up an official visit.

The two other probes involving Netanyahu centre on the premier allegedly receiving luxury gifts from wealthy supporters and suspicions he sought a secret deal for favourable coverage with the publisher of top-selling daily Yediot Aharonot.