A credit card bill of £6.5m was run up by staff at a quango tasked with making police forces in England and Wales more efficient, disclosures after a freedom of information request have revealed.
The National Police Improvement Agency (NPIA) incurred the costs in the financial years 2008-9 and 2009-10.
Spending on commemorative coins and karaoke equipment was revealed.
The NPIA said it is "bearing down" on spending but there was a "perception of wastefulness" in its "early days".
It said it had "significantly reduced" the amount spent through the use of credit cards by 33%, from £3.6m in 2009-10 to £2.48m in 2010-11.
Ministers plan to phase out the quango, which was set up in 2007 to help forces in England and Wales to save money.
Its functions will be transferred elsewhere.
Much of the costs by staff at the quango were incurred as a result of train or airline tickets and hotel accommodation for staff who travelled on business.
However, a taxi bill of nearly £100,000 has been revealed along with expenditure on a diverse range of items including £828 on judo apparatus, £105 on pottery, £55 on karaoke equipment - and £28 on lingerie.
The government is reviewing the use of so called "procurement cards" in Whitehall.
It plans to publish all expenditure incurred on them above £500 from next month.
Nick Gargan, the NPIA's chief executive, said: "We have controls in place to ensure that the cards are only used where there is a business need and they have been properly authorised.
"The NPIA is a national policy agency which means getting out and about to forces, which will involve incurring business expenditure.
"Nevertheless, we accept that, in the early days of the NPIA, there was a perception of wastefulness."
Mr Gargan went on: "We have been bearing down on this and continue to scrutinise our spending carefully in the context of sharp budget reductions."
He said the agency would deliver £30m savings in the current financial year, adding that it delivered £54.5m savings in the previous year.