Innocent Drinks' bid to push the health benefits of its Superfoods range was dealt a blow this week when it was rapped for an advert describing a smoothie as a detoxification product.

The press advert said the pomegranate, blueberry and acai Superfoods smoothie was a "natural detox" drink that contained "even more antioxidants than the average five a day".

It came under scrutiny after a complaint to the Advertising Standards Authority disputed the product's detox qualities and the amount of antioxidants it contained.

The ASA upheld the complaint, saying the word "detox" could only be used to describe a product proven to flush toxins out of the liver - such as water - and that fruit smoothies did not fulfil this requirement.

The ASA also said there was not sufficient evidence to prove the claim regarding antioxidant levels.

Innocent had defended the claims in the advert, stating that the high level of antioxidants in the smoothie neutralised free radicals and removed toxins from the body.

However, the ASA argued this was not the same as removing toxins - and asked the company to provide evidence of clinical trials that had measured the antioxidant levels in a person's blood after they drunk an Innocent smoothie.

Innocent said it had not been aware such tests would be required and had not carried them out.

Richard Reed, Innocent co-founder, said: "Our definition of detox is a bit broader, and is about the concept of detoxing by eating good stuff, like fruit, to help counteract the bad. We have absolutely no intention of misleading people."

Innocent said it had not repeated the ad since it first appeared in October 2006 - and would not run it again.