Yeah, sorry about the source (and it should be taken with a large pinch of salt - the Mail can easily distort things), but they're the most recent news source in Google News for this:
World's cleverest man turns down $1million prize after solving one of mathematics' greatest puzzles
An impoverished Russian who has been called the world's cleverest man today said he does not need a $1million prize awarded by a prestigious American institute for solving one of the most intractable problems in mathematics.
Dr Grigory Perelman prefers to live as a recluse in his grim cockroach-infested flat in St Petersburg.
Told about the financial prize for solving the Poincare Conjecture which had confounded mathematicians for a century, he said through his closed front door: 'I don't need anything. I have all I want.'
...
Four years ago, after posting his solution on the web, he failed to turn up to receive his prestigious Fields Medal from the International Mathematical Union in Madrid.
http://www.dailymail.co.uk/news/worldnews/article-1259863/Worlds-cleverest-man-turns-1million-prize-solving-mathematics-greatest-puzzles.html