HC Deb 20 November 1984 vol 68 c95W
Mr. Terlezki

asked the Chancellor of the Exchequer what estimates are available to him of the amount of heroin seized by Her Majesty's Customs and Excise as a percentage of the total imported.

Mr. Hayhoe

Any estimates of the total amount of heroin entering the country can only be speculative. The range of those estimates which I have seen is wide and little, if any, reliance can be placed upon them. It follows, therefore, that estimating the percentage seized by customs would be unrealistic.