Russia's maths whiz, Grigory Perelman, has officially declined his one-million dollar prize for proving the famous Poincaré Conjecture. The scientist said he'd informed the Clay Mathematics Institute of his decision a week ago. Perelman thinks it is unfair to give him the prize because U.S. maths scholar Richard Hamilton contributed equally to the proof. In 2006, Perelman was awarded the Fields Medal - the Nobel Prize of the maths world - for his contributions to geometry. But he declined the medal and the money in this case too. The maths genius leads a reclusive existence in the suburbs of Saint Petersburg at his mum's place.