Britain was so concerned about reports from Iraq of an alarming increase in the number of babies being born with deformities that ministers asked the Red Cross to investigate the claims, it has emerged.
The Government took the action last year amid allegations that weapons used by US and UK forces in Iraq were linked to a rise in foetal abnormalities seven years after the invasion.
A letter written by the International Development Minister Gareth Thomas reveals that the Government contacted the International Committee of the Red Cross sometime before September last year.
Mr Thomas wrote to Clare Short, who resigned from the Government in protest over the war, in answer to questions she had posed on behalf of a constituent.
The legal case, which is being prepared for the High Court by Public Interest Lawyers, raises questions about the UK's role in the US-led offensive against the City of Fallujah in 2004 in which hundreds of Iraqis died.
After the battle, in which it is alleged that a range of illegal weaponry was used against the civilian and insurgent population, evidence has emerged of large numbers of children being born with severe birth defects.
Iraqi families who believe their children's deformities are caused by the deployment of the weapons have begun legal proceedings against the UK Government.