Had supermodel Jodie Kidd run off with the 2,000-diamond studded Maria Grachvogel dress she posed in for London Fashion Week, it would not have been covered.

A spokeswoman for jewellers VanPeterson.com, which supplied the 2,000 gems for the black chiffon dress with a thigh-high slit, said its Lloyd's policy did not insure against “model infidelity” – for example the model taking the dress herself.

In any case, the gown was driven away by security men minutes after the fashion show finished.

The spokeswoman added that the dress, which has a reserve price of £250,000, is being auctioned to raise funds for the Nelson Mandela Children's Fund which helps orphans of Aids victims.