Dairyground
I seem to recall reading something recently to the effect that booze and similar liquids bought in EU duty-free shops and on board UK (or EU?) operated aircraft would be supplied in approved transparent packaging and could be carried through security checks in that packaging. A quick search using a well-known search engine has not turned up a reference to such a statement, although it did find reports of a European Decision to extend such a facility to goods purchased in airports outside the EU where security was believed to be up to ICAO standards.
My search did find specific rules for transit through Australian airports. generally it can't be done, but there is a hint of an exception similar to that proposed by the EU. In Sydney, and possibly at other entry points into OZ, it is possibly to buy at duty-free shops on arrival. The new finger-printing regime at Heathrow may provide similar facilities there.