NEW DELHI, March 21 (Xinhua) -- India has issued a special postal cover on Stephen Hawking as a tribute to the celebrated British physicist.

The special cover has been released by India Post in Mumbai, the state-owned postal service, nearly a week after his death, a senior official said Wednesday.

The physicist, known for his ground-breaking work on black holes and relativity, passed away at his home in Cambridge, Britain, on March 14, aged 76.

He had been confined to a wheelchair since the age of 22 when he was diagnosed with a rare form of motor neurone disease.

Indian Prime Minister Narendra Modi condoled Hawking's death as "anguishing".

"Professor Hawking's pioneering work made our world a better place. May his soul rest in peace," Modi tweeted after his death.