British banking giant Standard Chartered has been accused of scheming with Iran’s government to hide more than $250 billion (£160 billion) in illegal transactions for over 10 years from the US authorities.

The New York State Department of Financial Services (NYSDFS), in an explosive legal order last night, accused the New York branch of Standard Chartered of leaving the US financial system “vulnerable to terrorists, weapons dealers, drug kingpins and corrupt regimes” through its “flagrantly deceptive actions” between 2001 and 2010.

The US regulator in its report said that when a US colleague warned the bank about dealings with Iran, a Standard Chartered executive replied, “You f—ing Americans. Who are you to tell us, the rest of the world, that we’re not going to deal with Iranians.”

Standard Chartered has been called to appear before regulators on August 15 to explain the apparent violations and defend its licence to trade on the New York Stock Exchange. The latest probe for Standard Chartered comes after another British bank HSBC was accused of allowing drug cartels and rogue states to hide billions of pounds through its US arm.

However, the banking titan has strongly rejected claims of the New York regulators, saying that it had “ceased all new business with Iranian customers in any currency over five years ago”.

“The Group’s review of its Iranian payments also did not identify a single payment on behalf of any party that was designated at the time by the US Government as a terrorist entity or organization,” Standard Chartered said in the statement today.”

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