Gary Foster, a former vice president in Citigroup's treasury finance department was arrested in New York after returning from a flight out of Bangkok.

According to the FBI, Foster transferred money from various accounts to Citigroup's cash account and then to his personal account at a different bank in eight separate wire transfers. Foster is alleged to have used bogus derivatives deal numbers to create the appearance that the transfers were in support of an existing contract.

The illegal transfers were spotted during an internal audit and the evidence handed over to the FBI.

US attorney Loretta Lynch says: "The defendant allegedly used his knowledge of bank operations to commit the ultimate inside job."

Foster is scheduled to appear at the US Magistrates court in New York for an initial hearing. If convicted, he faces faces a maximum sentence of 30 years' imprisonment on the bank fraud charges.