Luxury chocolate maker Green & Black’s has been pulled up by advertising watchdogs for making exaggerated claims about the uniqueness of its products.

The Advertising Standards Authority upheld two complaints against a poster campaign on the London Underground which boasted “that’s what chocolate’s supposed to taste like”.

The ad also claimed that Green & Black’s chocolate tasted “different” from rival offerings because the company used cocoa butter instead of the vegetable fat used by some manufacturers.

However, prompted by a single complaint from a “consultant in oils and fats”, the ASA ruled that Green & Black’s had wrongly implied that other manufacturers didn’t use cocoa butter. In fact most used it to make dark chocolate, it said.

The ASA also agreed with the complainant that there was no evidence to show that vegetable fat affected taste. It told Green & Black’s not to repeat either claim in future advertising.