In August 2017 Ethical Consumer viewed the family tree for the Highland Spring company group on the corporate database Hoovers.com.
The database showed that the ultimate parent company, Park Tower Holdings Establishment, was based in Liechtenstein.
The company also had holding companies in the British Virgin Islands and Gibraltar.
These jurisdictions were considered by Ethical Consumer to be tax havens at the time of writing.
As a result the company received Ethical Consumer's worst rating for likely use of tax avoidance.

Reference:

Generic Hoovers Ref (2017)