Explosive new evidence has emerged over claims that thousands of children suffered birth defects after their mothers took a controversial pregnancy-testing drug.

Hundreds of families have for years been battling for compensation over claims the hormone-based drug Primodos led to their children suffering severe deformities and serious health problems.

Until now, campaigners have failed to establish a causal link between the drug prescribed by GPs during the Sixties and Seventies and the birth defects. But the discovery of thousands of pages of previously unseen documents has given them new hope of justice.

The papers, which were unearthed in the Berlin National Archives, will be examined by a committee of experts.