http://www.npg.org.uk/about/FAQ/how-much-i...ction-worth.phpQUOTE
a public institution
Couldn't find much information on funding, but as entrance is free I am guessing it's either entirely or mostly taxpayer money... Not very ethical of them to be so draconian about people being able to view the art from there without needing to visit their website, that's more how you'd expect a for-profit corporation to act...