US and Egyptian authorities have charged 100 people in what the director of the FBI has called "the largest international phishing case ever conducted".

The US and Egyptian fraudsters were accused of using phishing scams to steal account details from hundreds, possibly thousands, of people, and transferring about $1.5 million into fake accounts they controlled.

The group of fraudsters were accused of targeting US financial institutions and victimising a number of account holders by fraudulently using their personal financial information after they were successfully phished.

The arrests were the result of an investigation called Operation Phish Phry'. Starting in 2007, FBI agents worked with US financial institutions to "identify and disrupt" criminal phishing gangs.

"This international phishing ring had a significant impact on two banks and caused huge headaches for hundreds, perhaps thousands of bank customers," said Acting US Attorney George S. Cardona, in a statement.

"Organised, international crime rings can only be confronted by an organised response by law enforcement across international borders, which we have seen in this case."

American authorities charged 53 people, while Egypt charged 47, with offences including conspiracy to commit bank fraud, computer fraud, money laundering and aggravated identity theft. The bank fraud alone could lead to jail sentences of 20 years.