CONSTABLE'S masterpiece The Hay Wain has been arrested in central London amid claims of nude horse exploitation.
The archetypal English rural scene, painted in 1821, features a pair of semi-naked horses pulling two fat men in a big cart through a stream.
Superintendent Bill McKay said: "The painting is now in custody where our experts can study it to see if it makes them come over all unnecessary."
Constable used to spend summer weekends near Flatford Mill in Suffolk, where he would coax horses to pose nude while he sketched them in charcoal.
On several occasions the horses would be invited to his studio in London where he would create risqué watercolour cartoons and sell them to Members of Parliament.
It was at Flatford in 1821 that he paid two fat men in a cart to pose with their wet, scantily-clad horses while on their way to a toddler fight.
A spokesman for the RSCPA said: "Horse exploitation makes me so angry. Grrrrrrrr.
"But when I see horses stripped down to their pants and trussed up like a couple of donkeys, I say, 'enough'."
He added: "As the pervert Constable is dead, the logical thing to do is arrest the painting itself. Examples must be made."