LUCKNOW: Mukhtar Ansari was subjected to slow poisoning in jail, Umar Ansari, the son of the gangster-turned-politician who died of cardiac arrest at a hospital in Uttar Pradesh's Banda, alleged early Friday.

The charge has been denied by authorities.

Mukhtar 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 on Thursday.

The 63-year-old 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.

Mukhtar Ansari 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.

"My father had told us he was being subjected to 'slow poison'," Umar Ansari told reporters and added that the entire country knows about it now.

Mukhtar Ansari's brother and Ghazipur MP Afzal Ansari had on Tuesday alleged that he was being subjected to "slow poisoning" in jail.

On Friday morning, people had gathered at the Mukhtar Ansari's residence.

There was a large deployment of security personnel around the house as well as the hospital.

"We don't have any information about when the postmortem will be done. We were hoping that the postmortem would be done in the night itself and the body would be handed over to us in the morning. I don't understand why the administration is delaying it," Sibgatullah Ansari, Mukhtar Ansari's elder brother, told reporters.

When asked about the charges of "slow poisoning" levelled by Umar Ansari, he said, ".Mukhtar Ansari had informed the court through his lawyers in writing that these things are happening."

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

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

According to a medical bulletin, he 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 videographer. 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.

Uttar Pradesh Director General of Police Prashant Kumar had said on Thursday that prohibitory orders under the section 144 of the CrPC have been imposed across the state and teams of the Central Reserve Police Force along with the local police deployed in Banda, Mau, Ghazipur and Varanasi.

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 had said.