Sands, speaking out for the first time since the controversy came to light earlier this week, denied a number of claims made by the New York State Department of Financial Services.

Sands admitted some deals did violate US sanctions but these amounted to only 300 transactions worth about $14m.

New York’s State Department of Financial Services claimed earlier this week the US unit of the bank had for nearly a decade illegally hid 60,000 transactions with Iran.

Sands said the transactions were “administrative or understandable mistakes”.

“This was clearly wrong and we are sorry that they happened,” said Sands.

“However, there was no systematic attempt to circumvent sanctions.”

Sands also criticised the US authorities for giving no prior warning to the business, and questioned the accuracy of the allegations.

“We were surprised in the manner of the announcement and that it was done without giving us any notice,” he said.

“Frankly, there is a lot of material from the US regulators which we do not recognise or understand, or that is factually inaccurate.”

Sands also reiterated the group has disclosed to US authorities 99.9% of the transactions relating to Iran complied with the U-turn regulations.

Shares in Standard Chartered rebounded yesterday, gaining 7% or 87p to £13.15, after giving up as much as 25% on Tuesday once the money-laundering allegations surfaced.

This morning they climbed further, up 3.2% or 42.81p, to £13.58.