An active ingredient from a brown seaweed, off the coast of Brittany, may help kill pimples and oily skin.

Hoisted up from the seabed and converted into an extract for acne treatment, it goes on sale across Britain.

Human trials have shown that the seaweed extract cream had a positive impact, said the manufacturer, reports the Daily Mail.

It said in a trial of 60 males aged 12 to 24 with mild acne, products containing seaweed extract were significantly more effective than a dummy face wash, scrub or gel.

Enzo Berardesca, a director at the Instituto Dermatolgico San Gallicano in Italy who supervised the trial, described the results as 'extremely good'.

'Patients with mild to moderate acne, such as blackheads, whiteheads and skin redness, found their symptoms markedly reduced,' he added. Most importantly, there were no side effects.