The move to obtain testimony from ex-National Security Adviser Yaakov Amidror is the latest twist in a complex billion-dollar civil lawsuit launched in a New York court in October 2012 by the Israeli families of eight teenagers shot dead by a Hamas gunman at a Jerusalem seminary in 2008.
The families claim the Bank of China "facilitated" the attack and dozens of others by allowing wire transfers to the tune of millions of dollars to the Palestinian Islamist movement Hamas, via its New York City branch in violation of US law.
A key aspect of the families' case was expected to be the testimony of former Israeli intelligence agent, Uzi Shaya.
But the case took an unexpected turn earlier this month when the Israeli government filed a motion to block Shaya from testifying, saying it would "harm Israel's national security."
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Shurat HaDin, the Israeli group representing the families, has accused the government of Prime Minister Benjamin Netanyahu of caving into pressure from Beijing to protect lucrative trade ties.
In a counter move, Shurat HaDin has asked to cross-examine Yaakov Amidror, who stepped down as Israel's National Security Advisor earlier this month and whose name was on the affidavit accompanying the government's motion.
"We have a right to cross-examine him," she told AFP.
"We want to understand why the issue (of Shaya testifying) suddenly became a 'national security issue' after Netanyahu's visit to China."
"Once Israel admits that the reason it is prohibiting the testimony is pressure from the Chinese, it would be a clear case of obstruction of justice and destroying evidence by the Bank of China," she said.
Between 2005 and 2007, a group of Israeli officials, including Shaya, tried to negotiate with the bank in a bid to convince them to shut down all accounts used for transferring funds to Hamas and its smaller Islamist rival, Islamic Jihad.