Jake Chapman: He and his brother were shortlisted for the Turner Prize

Jake and Dinos Chapman - known for their shocking sculptures - were named on Thursday as this year's winners of the annual Charles Wollaston award at the London academy.

Their winning exhibit is entitled The Marriage of Reason and Squalor. The bronze sculpture is painted to look like clay. On one side it depicts an elephant's face and a pig's on the other.

The Royal Academy's Summer Show is one of the largest open contemporary art exhibitions in the world.

Anyone can enter a work, with the result that the exhibition is respected for its enviable mix of work from the celebrated and the obscure.

The Chapman brothers are one of the better-known exhibitors in this year's show.

The winning work is a double-faced bronze

They were also shortlisted for the 2003 Turner Prize. But the Charles Wollaston is their first major art prize.

Their work mixes imagery from diverse sources in an attempt to challenge taboos and accepted reasoning.

A number of the Chapman brothers' best-known works were included in the Royal Academy's successful, but controversial, Sensation exhibition.

It included diverse works from Charles Saatchi's Young British Artists collection.

Many of these are now on display in the new Saatchi Gallery at County Hall.

The Charles Wollaston award-winner is chosen by an independent panel of judges from the 1,242 exhibits on show.

The Summer Exhibition 2003 also includes works by internationally acclaimed artists such as Georg Baselitz, Peter Blake, David Mach and Robert Rauschenberg and the top UK architect Sir Norman Foster.