Whisky / Whiskey / Bourbon

I think you can bring in more than the 750ml limit or whatever it is, but you are supposed to pay the duty on everything above the limit. Also, you would probably have to convince customs that it was for personal use.

http://www.hmrc.gov.uk/customs/arriving/arrivingnoneu.htm#1

If you don't meet these conditions or you go over your allowance you'll have to pay any Customs Duty, Excise Duty and/or Import VAT due

Current rates here

So my understanding is that if I want to bring 10 750ml bottles of 40% rum back with me.. that's £1.25 each in Mauritius = £12.50
Excise duty would be based on there being 0.4*10*0.75 = 3l of pure alcohol, 3x£25.52 = £76.56
Customs duty would be (based on a commodity code of 2208 40 39 00, I think) €0.60/(0.4/0.075)+€3.20 = €3.1125

All plus 20% VAT = ~£110

So, about £1.25 in Mauritius, £11 a bottle in total after paying import duty :( I didn't include the duty-free allowance here, but it won't make much difference.