A law firm based in Oxford will defend members of a British Geological Survey team who are being sued after well water in Bangladesh was found to be contaminated with naturally-occurring arsenic.

The team from Manches are representing a division of the Oxfordshire-based Natural Environment Research Council in the action brought by a Bangladeshi, Binod Sutradhar.

Mr Sutradhar is a representative claimant on behalf of several hundred Bangladeshis who are suffering from arsenic poisoning and related diseases.

It is alleged that BGS was negligent in a 1992 research project to assess possible toxicity of groundwater to fish and humans.

The water quality tests were carried out in Crowmarsh, near Wallingford, by the BGS.

The writ alleges that BGS should have tested the water samples for arsenic, and that had they done so, Mr Sutradhar and many of his compatriots would have been able to avoid drinking water contaminated with arsenic.

NERC is defending the claim on grounds that it was not within the scope of the research project to test for arsenic.

They will also say that the scientists had no reason to suspect that arsenic was present in dangerous quantities in the groundwater.

Barristers Michael Beloff QC, Charles Pugh and Ben Cooper are acting for the scientists.

The problem arose after three million deep tube wells were sunk in Bangladesh in the 1970s and 1980s in an attempt to bring clean water to the drought-stricken country.

With support from Oxford-based development charity Oxfam, hospitals are retraining community health workers.

They now advise people to use ponds and rivers for drinking water supplies.