Vladimir Umanets: 'I was not defacing Mark Rothko work'

A man who allegedly defaced a painting by Mark Rothko at the Tate Modern in London has defended his actions.

Black on Maroon was written on with a small amount of black paint at about 15:25 BST on Sunday.

Vladimir Umanets told the BBC that his actions were in keeping with a movement called Yellowism and were not an act of vandalism.

First broadcast 8 October 2012