Buckingham Palace defended the travel costs Monday, and the National Audit Office said the expenses between 2003-2004 were all within the rules.
"The National Audit Office has totally exonerated the Duke from inappropriate use of public funds in his use of transport for official engagements," a spokeswoman for Buckingham Palace said on condition of anonymity.
But eyebrows were raised by the expenditure of nearly $5,600 for a 50-mile helicopter flight to attend a lunch in Oxford. The same trip by train would have cost $182, the audit report said.
"Travel by rail was considered but rejected as an option, based on the additional hour-and-a-half traveling time that would have been involved and the potential unreliability of the train arrival time," the report said.
The palace spokeswoman said reliability was an important factor because Andrew - the Duke of York - had to attend a state banquet in honor of Russian President Vladimir Putin, who was being escorted by the prince on his visit to Britain.
The report highlighted a trip for which Andrew chose a Royal Air Force flight costing some $8,900 in preference to a commercial flight that would have cost $477 "on the basis that this would save the Duke one hour's traveling time."
Details of the report on travel by Queen Elizabeth II's son first emerged in the Mail on Sunday newspaper. Andrew is fourth in line of succession to the throne.
The NAO report examined Andrew's travel costs after lawmaker Ian Davidson expressed concern about whether the prince was being wasteful and whether his sporting engagements had determined his mode of travel. The prince is an enthusiastic golfer.
The NAO concluded that "we did not find any cases where the mode of travel was determined by the Duke's sporting activities. Nor did we find any evidence that the Duke of York's official engagements were planned around golf."
However, the report contrasted Andrew's travel spending with that of other royals.
"For shorter journeys costing up to 2,500 pounds ($4,700), the Duke of York did not use either scheduled flights or rail services for any engagement. By comparison, other members of the Royal Family used scheduled flights or rail journeys more often," the
Davidson, a lawmaker with the governing Labour Party, urged the prince to rein in his travel spending.
"As far as I am concerned it comes across as viewing the public purse as bottomless and that he has been extravagant and wasteful," Davidson said. "I couldn't think of any example of frugality within the report."
By Michael McDonough