In black tie and tails, Bob Geldof is transformed from grungy eco-warrior to elegant senior statesman.

But while the Live Aid organiser certainly looked the part at a sumptuous ¡ê1,000 gala dinner at Hampton Court, he had managed to commit something of a faux pas.

The former punk rocker had loaded his jacket with more medals than is considered correct at the Raisa Gorbachev Foundation annual gala on Saturday night.

Bob Geldof: Medal-ing with tradition

Experts said it would have been more appropriate to wear the neck medal and breast badge of his honorary knighthood, awarded in 1986, to impress his host, former Soviet president Mikhail Gorbachev.

But he went too far, also pinning the miniature version of the same medal on his lapel bar. Last night experts said it is not the 'done thing' to wear both versions of the medal.

Geldof compounded the error by also wearing both versions of the rather obscure Sudanese Order of the Two Niles on his jacket.

The other two medals on his bar have been identified as the Chevalier dans l'Ordre des Arts et des Lettres bestowed by the French Government in January 2006, and a medal of the Legion d'Honneur, which was established by Napoleon.

Gedolf, 56, last night said he picked up the whole outfit from a costume shop, but medal historians confirmed that the regalia was all genuine.

William Spencer, from the National Archive, said: "It looks like Bob Geldof has duplicated the two types of medals on his dress. You should either wear the miniature medal bar or the larger medals instead.

"It is a real dress faux pas to wear them all at the same time. For Bob to be legitimately awarded these honours it would be very surprising for him to then pick some up from a costume shop."

Geldof has been awarded an assortment of international honours for his charity work and contribution to music.

He insisted the medals he was wearing were not his, adding: "I got them from a costume shop. A Russian fantasy type thing."