Dr Grigori Perelman, a reclusive Russian genius, is refusing to accept the prestigious $1 million "Millennium" mathematics prize awarded by the Clay Mathematics Institute in Cambridge, MA.

Perelman was awarded the prize for solving the one-hundred-year-old Poincaré conjecture, one of the most complicated mathematical problems in the world - so complex, in fact, that after Perelman posted his proofs in 2002 it took several years for other experts to confirm he was correct.

Now Perelman's refusal to accept the prize - the second prestigious prize he has refused - has led some to examine his unorthodox life and dub him "Mathsputin."

The 44-year-old Perelman currently resides with his mother and sister in his hometown of St. Petersberg, living extremely humbly. One neighbor told a Moscow newspaper, "He always wears the same tatty coat and trousers. He never cuts his nails or beard. When he walks he simply stares at the ground, rather than looking from side to side."

Another neighbor told of a time she had visited Perelman's apartment due to problems with cockroaches.

"I was once in his flat and I was astounded," she said. "He only has a table, a stool and a bed with a dirty mattress which was left by previous owners -- alcoholics who sold the flat to him."

After performing some teaching in American universities in 2003, Perelman has apparently given up on mathematics, dismayed at the intellectual and moral failings of his peers. Instead, according to reports, he likes to play table tennis against a wall in his apartment. "You are disturbing me. I am picking mushrooms," he told a journalist who managed to get in touch with him.

A number of appeals have been made to Perelman to accept the prize and give the money to charity. "Each suffering child and each mother entangled in circumstances of her life could receive help," wrote the chairwoman of one Russian children's charity.