Ansama Kamara, 31, was part of a gang who called the Olympic group claiming to work for contractor Skanska, appeared at Southwark Crown Court for sentencing.

Skanska work on the Olympic site, and the gang asked for £2.3 million ($3.7 million) of transactions to be paid into an account for which they provided details.

It was when Kamara tried to then send £2 million ($3 million) to Nigeria that he was discovered by transfer bureau officials.

The ODA have managed to recover the stolen cash, according to a spokesman.

"Early identification by the ODA greatly reduced the potential impact of this fraud with almost all of the monies recouped shortly after it occurred last summer," he said.

"Throughout the project we have worked with the Metropolitan Police Service to develop and refine our systems to meet the changing fraud risks and will continue to do so."

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