Air New Zealand are starting an Auckland - Hong Kong - London service in September. Their current route to the UK is Auckland - Los Angeles - London.
The main driver for the new route, to quote an Air NZ source, is as follows :
"the primary reason for introducing it is complaints from pax about the appalling treatment they receive from US Immigration in LAX on the 2-hour stopover from LHR to Auckland. Apparently thousands of pax have written in saying they love AirNZ but will travel via the Far East, i.e. on a different airline, in future to avoid being treated like criminals by officious US Immigration staff."