A former gangster turned politician passed away from cardiac arrest in the northern Indian state of Uttar Pradesh, authorities confirmed on Thursday.

Mukhtar Ansari, aged 63 and a five-time lawmaker from the state, had been incarcerated since 2005.

His family disputes the circumstances of his demise, alleging that he was administered a “poisonous substance” while in jail.

Security was heightened across the state as crowds gathered outside Ansari’s residence upon hearing the news of his passing.

Ansari, who once led his own gang during the 1990s, faced over 60 criminal charges, including 15 for murder.

Transitioning into politics, he secured his first state election victory in 1996 in his hometown of Mau and remained a legislator from that constituency until 2022.

In April 2023, Ansari was convicted for the killing of Krishnanand Rai, a lawmaker from the ruling Bharatiya Janata Party (BJP), and was sentenced to a decade in prison.

Earlier this month, he was handed a life sentence for a 1990 case involving counterfeit arms licenses.

Authorities in Banda district reported that Ansari was taken to the hospital after complaining of vomiting on Thursday.

“A team of nine doctors provided immediate medical attention,” stated a medical bulletin from Rani Durgavati Medical College. “However, despite their best efforts, he succumbed to cardiac arrest.”

Ansari’s brother, Afzal Ansari, a Member of Parliament from the state, alleged foul play, claiming his brother had been poisoned.

“Mukhtar stated that he was given a poisonous substance in his jail food,” Afzal Ansari told reporters. “This isn’t the first time. About 40 days ago, he was similarly poisoned. Recently, on March 19th and 22nd, he was poisoned again, leading to his deteriorating health.”

According to jail authorities, Ansari had been hospitalized on Tuesday after a fall in the washroom, receiving initial treatment within the prison before being transferred to the hospital for further care. He was discharged after 14 hours.

Following Ansari’s demise, Uttar Pradesh police imposed curfew orders and conducted flag marches in certain areas.

Ansari’s son, Umar Ansari, expressed frustration at the lack of information provided by authorities regarding his father’s health.

“Two days ago, I attempted to visit him, but was denied access,” he stated.

A post-mortem examination is scheduled for Friday.