A POOR Russian genius, who could be the world's cleverest man, says he does not need the $1 million prize for solving one of the hardest problems in mathematics.

Dr Grigori Perelman prefers to live as a recluse in his grim cockroach-infested flat in St Petersburg, the Mail Online reports.

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.”

The bearded genius, aged 44, was named last week as winner of the $1 million prize by the Clay Mathematics Institute in Cambridge, Massachusetts.

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.

At the time he stated: “I'm not interested in money or fame. I don't want to be on display like an animal in a zoo.

“I'm not a hero of mathematics. I'm not even that successful, that is why I don't want to have everybody looking at me.”

Neighbour Vera Petrovna said: “I was once in his flat and I was astounded. 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.

“We are trying to get rid of cockroaches in our block, but they hide in his flat.”

It was in 2003 that Perelman, then a researcher at the Steklov Institute of Mathematics in St Petersburg, began posting papers online suggesting he had solved the Poincare Conjecture, one of seven major mathematical puzzles for which the Clay Institute is offering $1 million each.

Rigorous tests proved he was correct.

The topological conundrum essentially states that any three-dimensional space without holes in it is equivalent to a stretched sphere.

The puzzle was more than 100 years old when Perelman solved it - and can help determine the shape of the universe.

After 2003 Perelman gave up his job at the Steklov Institute. Friends have been reported as saying he has resigned from mathematics altogether - finding the subject too painful to discuss.

Read more about Grigori Perelman and the Poincare Conjecture at the Mail Online