Raipur: Rights activist Dr Binayak Sen was sentenced to life imprisonment on Friday after being convicted of sedition for helping Maoist rebels in a case that has drawn widespread international attention.

His shaken family called it a sad day for Indian democracy while fellow activists reacted with disbelief and vowed to appeal.

As Sen, 59, clad in a kurta-pyjama and looking his frail self, looked on, district and sessions court judge B.P. Varma convicted him on a variety of counts such as 124 A and 120 B of the Indian Penal Code and also under the Chhattisgarh Special Public Security Act and the Chhattisgarh Unlawful Activities Prevention Act.

Maoist ideologue Narayan Sanyal, in his 80s, and 30-year-old Kolkata-based businessman Piyush Guha were also convicted. They are already in judicial custody and were present in court.

Sen was, however, acquitted of waging war against the state.

A doctor by profession, Sen was out on bail but was taken into custody soon after the judgement. He had been arrested in 2007 from Bilaspur for alleged links with Sanyal but released in May 2009 at the behest of the Supreme Court.

Punishment for sedition can range from a few years in jail to life imprisonment.

His wife Illina said at the court building: "I totally disagree with the court's decision. There is no evidence against him. We will go to the high court.

"One who has worked for the poor of the country for 30 years, if that person is found guilty of sedition and conspiracy - when gangsters and scamsters are walking free - I think it's a scandalous situation.

"I am sad. I am sad because my daughters, my husband and I will have to fight another long legal battle. I don't how long will this be. I am even more sad for the state of Indian democracy," Illina said.

The family was visibly shaken.

"I lost my voice, please leave me," Binayak Sen's distraught brother Dipankar, in tears, told reporters at the court.

Binayak Sen is a vice president of the People's Union for Civil Liberties (PUCL).

"This is a fabricated case by the Chhattisgarh government and police. We will go for appeal," said PUCL national general secretary Kavita Srivastava.

Rights activists had thronged the trial court ahead of the verdict. Police had sounded an alert in an around the court premises.

"I am shocked. We never expected this because there was not a shred of evidence against him. This is a sad day for our democracy," Mahipal Singh, secretary of PUCL, told IANS in New Delhi.

"We have just got the summary of the judgment, so it will take some time for us to decide the legal course of action," he said.

Since coming to Chhattisgarh in 1981, Sen had spent much of his time to bring healthcare to tribals in the impoverished tribal areas.

In 2008, when he was in jail, the US-based Global Health Council awarded him for his work in global health and human rights. The same year, a group of 22 Novel laureates condemned Sen's incarceration.

The case against Binayak Sen continued even as Maoist guerrillas stepped up attacks on security forces in Chhattisgarh, killing scores of them. The state's Bharatiya Janata Party government has been accused of acting tough against rights activists.