The House of Commons public accounts committee questioned these estimates after the Scottish Whiskey Association put the figure at between £100m and £150m, and also follows a National Audit Office report which questioned the reliability of statistics used by Customs to estimate the level of spirits fraud.
The PAC said these figures were ‘riddled with uncertainty’.
Comments by the all-party committee come just days before next week’s Budget which could include costly changes to the way distilleries pay tax.
Edward Leigh, chairman of the PAC said: ‘Clearly, it would be unwise for Customs to place too much reliance at present on their own figures.’
Brown wants to force manufacturers to pay for ‘tax stamp’ labels to stick on bottles at the distilleries, something which is being vigorously opposed by whiskey makers.
Total VAT fraud is estimated at £12bn annually.
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