The research looked at how consumers judged a company's ethical responsibility and product offering, and what information they trusted.
Out of a list of 15 different sources of information, packaging was cited by consumers as the most trustworthy, followed by consumer watchdogs and family and friends.
Trailing at the end of the list were celebrity endorsements, cited as being less trustworthy than only one other source: door-dropped leaflets.
It comes as bad news for celebrities such as David Beckham, whose resignation as England captain earlier this month has already called into question his value as a brand spokesman.
The 'What Assures Consumers?' survey was conducted by Globescan for AccountAbility, the international body that promotes accountability for sustainable development, and the National Consumer Council.
Philip Monaghan, director at AccountAbility, said: "It appears that sole reliance on celebrity influencers like David Beckham is waning due to an increasingly sceptical public. To assure consumers, a key tactic in the game plan for success, is a better understanding among companies of how to select the right mix of 'messengers' from those available."
The full list of channels, starting with the most trustworthy:
1. Packaging
2. Consumer watchdogs
3. Family and friends
4. Trusted third-party 'standard' logos
5. Store salespeople
6. Consumer TV programmes
7. Company websites
8. Advertising
9. In-store promotions
10. Internet sources not controlled by the company
11. Press articles
12. Government departments
13. NGOs and campaign groups
14. Celebrities
15. Leaflets delivered to home
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