Three senior judges upheld a pre-nuptial agreement in a case involving one of Germany’s richest women and her £30,000-a-year former husband, a biotechnology researcher at Oxford University.

In a landmark judgment, the Court of Appeal rejected an argument by the husband that such agreements were not legally binding in this country.

Heiress Katrin Radmacher — said to be worth £100m — had challenged a ruling that she should give £5.85m to Nicolas Granatino, despite him signing a contract vowing never to make claims on her if they split up. They divorced in 2006.

Mr Granatino, 37, is expected to take the case to the House of Lords.