New Delhi, May 13 : The People's Union for Civil Liberties (PUCL) today called for the immediate release of social worker Dr. Binayak Sen, and appealed to the Central Government to allow him to travel to the United States to receive the Jonathan Mann Award for Global Health and Human Rights.

Dr. Sen, a pediatrician, had been attempting to promote a low cost health plan in several villages of Chhattisgarh and was a vociferous critic of the Salwa Judum movement, a state government-sponsored initiative to counter Maoist killings in the state.

Former Delhi High Court Chief Justice and former PUCL president Justice (retired) Rajinder Sachar said that the Central Government must intervene in the matter at the earliest.

"He is also being prosecuted for unlawful activities under the Chhattisgarh Act. We do feel that Central Government has a right to look into the matter and at least advice the Chhattisgarh Government about their views. There is nothing wrong in it. It is part of a Constitutional set up. There is a worldwide protest on this. Surely it concerns the Central Government because it is no longer a local matter," Sachar added.

Hundreds of people are expected to take to the streets in protest across the globe on Wednesday (May 14) to mark the first anniversary of his arrest. The global protest is being planned in ten North American and three European cities.

Meanwhile, 22 Nobel Laureates and academicians have also reportedly appealed to the government to allow him to travel to the U.S. to receive the award.

Chhattisgarh Police arrested Dr. Sen on May 14 last year, charging him with waging war against the state, conspiracy, sedition and assisting Maoists.

Chhattisgarh is one of the worst affected states by Maoist violence. Over 40,000 tribal people have been moved to inadequate government-run camps in the state. A human rights group says there is an "unacknowledged civil war" in the area.

Around 13 of India's 29 states are affected by Maoist violence.