The French authorities are investigating the death of a British man who died in July after clearing algae from a beach in Brittany. At the time it was thought that the algae only emitted an unpleasant odour but the fumes released are now known to be toxic.

The dead man's family initially refused a further investigation into the cause of death but have since changed their minds. If the toxic fumes are found to be the culprit, extra measures will have to be taken to ensure that other people involved in removing the algae are sufficiently protected.

The algae are not dangerous in the sea but release toxic fumes when they rot on the beach. Researchers warn that inhaling the fumes can prove fatal within a matter of minutes.