Reclusive Russian mathematician Grigory Perelman, who shot to global fame after claiming to solve the seemingly intractable Poincare conjecture, has refused another prize for the achievement.

The Clay Mathematics Institute (CMI) said that Mr Perelman informed the Cambridge, Massachusetts-based research center that he would not accept its million-dollar prize.

"I have turned down (the award)," Mr Perelman told the Interfax news agency by telephone. "The main reason is disagreement with the organised mathematics community. I do not like their decisions, I consider them unfair."

"I think that the contribution of American mathematician (Rich-ard) Hamilton in solving this problem is no less than mine."

On June 8 and 9, the institute held a conference in Paris to celebrate Mr Perelman's resolution of the Poincare conjecture, a riddle on properties of multi-dimensional space that had perplexed mathematicians since it was coined by Frenchman Henri Poincare in 1904.

The prize was announced after teams of experts examining his findings found Mr Perelman's solution to be flawless.

CMI said it would announce in the fall how the prize money turned down by Mr Perelman "will be used to benefit mathematics."

Mr Perelman, who is also known as Grisha Perelman, already has a long history of turning down awards and not showing up at award ceremonies.

He published his findings on the internet in 2002 and 2003, and by 2006, Mr Perelman was awarded the mathematics world's version of a Nobel prize, the Fields Medal, as experts said he had indeed worked it all out.

But the 44-year-old mathematician became the first person to turn down a Fields Prize, awarded every four years since 1936, saying he did not want to be a figurehead for the mathematics community from which he says he has withdrawn.

The Poincare conjecture is regarded as one of the most important questions in topology, a geometry-related branch of mathematics which deals with spatial properties.

In simple layman's terms, it asserts that any shape without a hole can be stretched or shrunk into a sphere.