Dame Anita Roddick has admitted that she harbours concerns over the ethical record of Nestlé, a major shareholder in the French cosmetic giant L'Oréal, which bought the Body Shop for £652m.

She also suggested campaigners, determined to stage a consumer boycott, should target the Swiss multinational's leading brands such as Perrier, Kit-Kat and Nescafé, rather than the company she founded.

The entrepreneur has been repeatedly forced to defend herself over the controversial sale in March, announced amid a blaze of allegations that she had morally and financially sold out.

Pressure groups reacted with fury - not least because L'Oréal has faced persistent allegations over its record on animal testing - but also because the company is 28 per cent-owned by Nestlé. It has been the target of a long-running campaign centred on its alleged promotion of powdered milk in the developing world.

In a letter to the campaign group Baby Milk Action, which had asked Dame Anita to justify the sale, she defended the record of the Body Shop and those who sought to bring about change from inside "the black hole of the corporate world".

However, she conceded: "Yes I object to the way Nestlé behaves. I am aware of their track record on baby milk, GMOs and Ethiopia, you [would] have to [have] been living in space not to know of their reputation."

She also sought to distance herself from the company. "I'm not an investor in Nestlé myself. I'm not giving them any money. I'm not even taking money from them. I am taking money from a company where they have a small stake, and ... I will be giving this away to further the cause, just as I did last year to help Amnesty move into a new office." But she also warned that a consumer boycott could be counter-productive.

"(They) rarely work and the people you hurt are primarily the weak and the frail. And when all you do is boycott then there is no chance of getting a lever on the way the world is," she said.

"So if you have to bloody boycott - then boycott. Boycott all the products that Nestlé own 100 per cent - Perrier, Kit-Kat, Shredded Wheat, Nescafé, Carnation Milk. And boycott every pension fund that may have holdings in Nestlé for whatever reason, and everyone who benefits from them. But for goodness sake strengthen the arm of anyone who sees an opportunity of changing the black hole of the corporate world."

Mike Brady of Baby Milk Action accused Dame Anita of "backtracking" over Body Shop's long-standing support for consumer activism. The group plans to press ahead with the national protest against the company's outlets on 20 May which coincides with the 25th anniversary of the adoption of the International Code of Marketing of Breastmilk Substitutes.

"We cannot ignore the fact that buying Body Shop products will put money in the coffers of Nestlé. Our supporters want to know where the money goes and 99 per cent in an online survey we conducted said they would add Body Shop to their personal boycott list and seek ethical alternatives," he said.

Last week Body Shop posted a strong set of trading figures with sales across the group up 5 per cent in the eight weeks following the announcement of the L'Oréal take over. Critics say the failure to reveal UK trading could mask the affect of a boycott.

Nestlé defended its ethical record, saying it made "continual efforts" to comply with World Health Organisation guidelines on marketing. "An annual survey of 20,000 people in 20 countries by Globescan (Toronto and London) found Nestlé to be among the top companies spontaneously named as socially responsible, particularly in the developing world," it said.