Indian authorities insisted that a controversial case against a jailed human rights activist will go forward, with one official saying Wednesday that a group of Nobel laureates pressing for his freedom have no respect for the law.

Dr. Binayak Sen, a prominent physician and outspoken government critic who has long worked among India’s most impoverished people, is being tried in the eastern Indian state of Chattisgarh for allegedly aiding the region’s communist rebels, known as the Naxalites.

The case has become a cause celebre in Indian intellectual and activist circles. Earlier this month, a group of 22 Nobel laureates _ ranging from medicine winners to economics honorees _ sent a letter to India’s president and prime minister expressing their concerns about the case against the 58-year-old physician.

“Dr. Sen appears to be incarcerated solely for peacefully exercising his fundamental human rights,” the group wrote in its May 9 letter.

Sen was also recently awarded the 2008 Jonathan Mann Award for global health and human rights. The Nobel laureates’ letter urged authorities to allow him to personally receive the honor at a ceremony in Washington on May 29.

But Indian authorities say Sen, who has been jailed for more than a year and denied bail, must remain in prison and that his trial will go forward.

“There appears to be a move to decide judicial matters in an extrajudicial way,” said N. N. Baijendera Kumar, a spokesman for the Chattisgarh government, referring to the letter. “Those demanding his release don’t have respect for law.”

Prime Minister Manmohan Singh’s office, meanwhile, said it had no knowledge of the letter, which has been widely reported in the Indian media.

The charges against Sen stem from visits he made to a jail in Raipur, the capital of Chattisgarh, where he treated Naxalites and other prisoners. Authorities say he used those visits to pass notes between jailed Naxalite leaders and their compatriots in the field.

Sen has insisted he only provided medical treatment during his visits. Passing notes, he maintains, would have been impossible because his visits were closely supervised by prison guards.

Sen has spent the past half century arguing that government efforts to develop vast tracts in Chattisgarh, a largely rural state that is among India’s poorest, are harming the area’s indigenous peoples, known here simply as “tribals.”

He has worked in tribal villages and repeatedly tied to rally people to their cause, often invoking the ire of authorities.

Sen’s trial continues on June 25. If convicted, he faces up to seven years in prison.