Hearing an appeal filed by Abubacker, seeking his release from the jail on medical grounds, the court also issued a notice to the National Investigation Agency (NIA) on the appellant's application, in which he has sought the placing of certain documents on record.

The court asked the NIA to file its response on the factual assertions made in the application and listed the matter for further hearing on March 13.

"In the meantime, the medical superintendent of Tihar Jail is directed to ensure that the appellant is provided efficacious treatment for all his illnesses on a regular basis," a bench of justices Siddharth Mridul and Talwant Singh said.

Abubacker has filed the appeal challenging a trial court order that refused to release him on medical grounds.

Abubacker was arrested by the NIA during a massive crackdown on the PFI, a banned organisation, last year and is presently in judicial custody.

Advocate Adit Pujari, appearing in the court on behalf of Abubacker, submitted that an affidavit has been filed detailing the recent position and his medical condition in jail, based on a "virtual mulakat".

"He has a 'sevadar' (assistant) with whom he cannot even communicate as his languages are only Malayalam and English. This is the first and only case against him. He has been a school teacher. He is someone who is 71 and seeing the confines of a prison for the first time," Pujari said.

The NIA's counsel, however, referred to a video showing Abubacker addressing thousands of people in Hindi.

The premier investigating agency had earlier told the court that Abubacker was trying to derail the process of investigation by filing pleas regarding his medical condition simultaneously before the trial court and the high court.

It had said the investigation against him was pending and he was getting the best possible medical treatment.

Abubacker's counsel had earlier said his client had a right to health and live with dignity and was not able to clean himself after responding to nature's call due to multiple ailments.

The high court had observed that the case against Abubacker was lodged under the provisions of the Unlawful Activities (Prevention) Act (UAPA), which does not pertain to trivial offences.

It had said when the appellant's grievance was with respect to receiving medical treatment on account of his ill health, he had to be sent to a hospital, instead of being sent home.

The appellant's counsel had said his client's health condition was serious and "only treatment would not suffice" but post-treatment care would also be required, and urged the court to grant him interim bail for six months.

The court was informed earlier that Abubacker was suffering from cancer and Parkinson's disease and was in "great pain", which needed urgent medical supervision.

The court had refused to put Abubacker under house arrest and said he would be admitted to a hospital for treatment, if required.

It had observed that there was no provision in law for a "house arrest", but directed that Abubacker be "escorted safely" in custody to the All India Institute of Medical Sciences (AIIMS) here for an oncosurgery review.

A large number of alleged PFI activists were detained or arrested in 11 states and Union territories during the massive raids preceding a nationwide ban imposed on the organisation on September 28, 2022.

In the near-simultaneous raids carried out across the country as part of a multi-agency operation spearheaded by the NIA, a large number of PFI activists were detained or arrested for allegedly supporting terror activities.

The arrests were made in Kerala, Maharashtra, Karnataka, Tamil Nadu, Assam, Uttar Pradesh, Andhra Pradesh, Madhya Pradesh, Puducherry, Delhi and Rajasthan.

The government banned the PFI and several of its associate organisations on September 28, 2022 for five years under the stringent anti-terror law UAPA, accusing these outfits of having "links" with global terror groups like the IS