Twenty-two Nobel laureates from around the world have appealed to the Indian government to release jailed human rights activist Binayak Sen.
The appeal has been made in a letter to India's president and prime minister.
They say Dr Sen should be allowed to travel to the US to receive the Jonathan Mann Award for Global Health and Human Rights announced in April.
Dr Sen has been held in prison accused of links to Maoist rebels for nearly a year. He denies the charge.
The Nobel Prize-winning scientists and economists said in the letter that Dr Sen should be allowed to receive the award in Washington on 29 May.
"We also wish to express grave concern that Dr Sen appears to be incarcerated solely for peacefully exercising his fundamental human rights," the letter said.
This is "in contravention of Articles 19 (freedom of opinion and expression) and 22 (freedom of association) of the International Covenant on Civil and Political Rights - to which India is a state party - and that he is charged under two internal security laws that do not comport with international human rights standards," it added.
A press release issued by Free Binayak Sen Campaign says hundreds of people across the globe will be holding protest demonstrations on 14 May - the first anniversary of his arrest - demanding his immediate release.
Campaigns are planned across several Indian cities including Delhi, Madras (Chennai), Mumbai, Bangalore and Calcutta.
Protests will also be held in London, Paris, Stockholm and Toronto and 10 north American cities including New York.
Conferring the award on Dr Sen last month, the Global Health Council said he was chosen for his services to poor and tribal communities.
He was also chosen for what the council called his unwavering commitment to civil liberties and human rights.
Dr Sen is also the vice president of the Indian human rights group People's Union for Civil Liberties.
The Mann award is given yearly in memory of Dr Jonathan Mann, an epidemiologist who set up the World Health Organisation's first Aids programme.
The award was decided by an international jury of public health professionals.