Jailed gangster-turned-politician Mukhtar Ansari died of cardiac arrest at a hospital in Banda in Uttar Pradesh on Thursday.

Prohibitory orders under Section 144 of the Criminal Procedure Code (CrPC), which bars large gatherings, were imposed across the state and additional security personnel deployed in the Banda, Mau, Ghazipur and Varanasi districts.

Ansari was brought to the Rani Durgavati Medical College in Banda from the district jail in "an unconscious state" and, according to its principal Suneel Kaushal, he died at the hospital following cardiac arrest.

Ansari's brother and Ghazipur MP Afzal Ansari had on Tuesday alleged that he was being subjected to "slow poisoning" in jail, a charge denied by the authorities.

Ansari (63) was a five-time MLA from Mau Sadar. He had been behind bars in Uttar Pradesh and Punjab since 2005. He had over 60 criminal cases pending against him.

He was sentenced in eight cases since September 2022 by different courts in Uttar Pradesh and was lodged in the Banda jail. His name was on the list of 66 gangsters issued by Uttar Pradesh Police last year.

Uttar Pradesh Director General of Police Prashant Kumar said prohibitory orders under Section 144 of the CrPC were imposed across the state and teams of the Central Reserve Police Force along with the local police deployed in Banda, Mau, Ghazipur and Varanasi.

Ansari, who hailed from Mau, was believed to have a strong influence in the adjoining Ghazipur and Varanasi districts as well.

The social media cell of the Uttar Pradesh Police has also been activated to keep a close watch on unlawful elements online, the police chief said.

According to a medical bulletin, Ansari was brought to the medical college around 8.25 pm on Thursday in an unconscious state after he had complained of vomiting. A team of nine doctors attended to him but he died of cardiac arrest, it stated.

Officials at the police headquarters in Lucknow said Ansari's post-mortem will be done in Banda and it will be videographed. The viscera will be preserved if needed, they said.

Earlier, Ansari was hospitalised for around 14 hours on Tuesday after he complained of abdominal pain.

In January 2019, Ansari, then a BSP MLA, was lodged in Punjab's Ropar jail in connection with an extortion case and remained there for more than two years. The Uttar Pradesh government approached the Supreme Court to bring Ansari back to the state.

AIMIM leader Asaduddin Owaisi condoled Ansaari's death and said despite serious allegations over the former MLA being poisoned, the state government did not pay attention to his treatment.

"Condemnable and regrettable," Owaisi said in a post in Hindi X.

The Samajwadi Party and the Rashtriya Janata Dal's (RJD) Tejashwi Yadav also condoled Ansari's death.

"Got the sad news of the demise of former UP MLA Shri Mukhtar Ansari. We pray to God to grant peace to the departed soul and strength to the bereaved family to bear the loss," Tejashwi Yadav said in post in Hindi on X.

"A few days ago he had complained that he had been poisoned in jail, yet it was not taken seriously. Prima facie this does not seem justifiable and humane. Constitutional institutions should take suo motu cognizance of such strange cases and incidents," the former Bihar deputy chief minister added.

"Sad demise of former MLA Shri Mukhtar Ansari. May his soul rest in peace. May the bereaved family members get the strength to bear this immense loss. Humble tribute," the Samajwai Party said in a post in Hindi on X.

Former Bihar MP Pappu Yadav, who joined the Congress recently, termed Ansari's death an "institutional murder" and demanded a court-monitored probe into it.

"Former MLA Mukhtar Ansari's institutional murder... It is like burying the law, Constitution, natural justice," Pappu Yadav said in a post in Hindi on X.

The Chief Justice of India should take "suo motu cognizance of this. There should be a court-monitored impartial investigation," the Congress leader said.

"He was making allegations for several days that he was being given slow poison. His MP brother also made this allegation. This is an indelible blot on the country's constitutional system," he added.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.