Townsend had just completed a two-year term as chairman of drinks trade charity The Benevolent, where he helped raise vital funds for members of the industry that had fallen on hard times.
He held several senior roles during a 30-year career in the trade, including managing director at Matthew Clark and at Louis Latour Agencies.
He had been at Treasury Wine Estates for the past six years, heading up its UK, Irish and European markets, and was 53 years old.
Treasury Wine Estates chief executive Michael Clarke said: “Our deepest condolences go out to Dan’s family and loved ones. Dan is a big part of our business and he has been a role model for many. This is an incredibly sad time for our entire business, in particular for our UK and European teams.”