Luke Duffy sentened to jail in an alleged $360 million unauthorised trading scandal.

Former senior National Australia Bank trader Luke Duffy has been sentenced to at least 16 months jail for his part in an alleged $360 million unauthorised trading scandal.

The 35-year-old former head of NAB's foreign currency options desk pleaded guilty to three charges of dishonestly using his position for personal gain.

Victorian County Court judge Geoff Chettle today sentenced Duffy, of Albert Park, to 29 months in prison with a minimum term of 16 months.

The sentence follows an 11-month investigation by the Australian Securities and Investments Commission into the alleged unauthorised trading in foreign exchange and foreign exchange options at the bank by four NAB traders.

Crown prosecutor Terry Forrest, QC, yesterday told a pre-sentence hearing for Duffy that the four traders made false claims about the profits made on the trading desk to avoid the scrutiny of management, to preserve their jobs, receive bonuses and avoid "some pretty tough questions".

Duffy has admitted to entering 19 false foreign exchange trades between October 2003 and January 2004, worth more than $260 million.

But John Dickinson, representing Duffy, denied that his client made the false trading claims to receive his bonus.

One of Duffy's co-accused is expected to appear before the Victorian County Court and the two others face a committal hearing in August.