Omar Abdullah, 49, has detained since August.

Omar Abdullah's sister Sara Abdullah Pilot has challenged his detention and charges under the stringent Public Safety Act (PSA) before the Supreme Court, asking for the former Jammu and Kashmir chief minister to be produced in court and freed immediately.

Sara Abdullah Pilot says her brother's detention is a grave violation of his constitutional rights including that of freedom of speech, and is part of a "consistent and concerted effort to muzzle all political rivals".

Omar Abdullah, detained without charges since August 5 -- when the government ended special status to Jammu and Kashmir under Article 370 -- was formally detained under the PSA last week.

Similar orders of detention had been issued over the last seven months "in a wholly mechanical manner" to others detained, Sara Abdullah Pilot says in her petition.

"The order conflates 'Governmental policy' with the 'Indian State', suggesting that any opposition to the former constitutes a threat to the latter. This is wholly antithetical to a democratic polity and undermines the Indian Constitution," the petition says.

"...a reference to all the public statements and messages posted by the detinue during the period up to his first detention would reveal that he kept calling for peace and co-operation - messages which in Gandhi's India cannot remotely affect public order."

Mr Abdullah was not even served with the material that formed the basis of detention, she says.

Details of the charges listed out in a dossier against the 49-year-old National Conference leader have sparked surprise and anger. His sister's petition says the dossier contains "patently false and ridiculous material", essentially accusing him of becoming a popular figure among general masses and possessing considerable influence over people.

The dossier, accessed by NDTV, includes his "ability to garner votes even during peak militancy and poll boycotts". It says Mr Abdullah, a former Union Minister, can influence people for any cause and specifically cites his ability to bring voters out in the wake of boycott calls by separatists. "The capacity of the subject to influence people for any cause can be gauged from the fact that he was able to convince his electorate to come out and vote in huge numbers even during peak of militancy and poll boycotts," it says.

Referring to this in her petition, Sara Abdullah Pilot says in other words, Mr Abdullah is accused of convincing people to participate in elections in huge numbers and exercise their democratic right to vote despite threats from militants.

Other charges include Mr Abdullah's opposition to the Centre's decision to abrogate Article 370 and "instigating people on Twitter against the unity and integrity of the Nation". No twitter posts have been cited to back up this allegation.

The dossier says he is a "popular figure among masses and has tremendous potential for diverting energy of common people for any cause".

Mr Abdullah's sister says in her petition that he had been accused of "favouring radical thoughts" and "planning and projecting his activities against the Union of India under the guise of politic" while enjoying the support of gullible masses. "These averments fly in the face of his tweets shortly before/ around the time of his detention, in which he cautioned people against resorting to violence and taking law into their hands," she argues.

These were Mr Abdullah's tweets on August 5.

Violence will only play in to the hands of those who do not have the best interests of the state in mind. This wasn't the India J&K acceded to but I'm not quite ready to give up hope yet. Let calm heads prevail. God be with you all. — Omar Abdullah (@OmarAbdullah) August 4, 2019

Mr Abdullah was in preventive detention under Section 107 of the CRPC since August 5, 2019. Under the law, his detention was to end six months later on February 5, 2020.

On February 5, the government used the Public Safety Act against him and another former Chief Minister, Mehbooba Mufti. This extends their detention by 3 months without trial and it can be extended for up to one year.