The capless man in a white printed shirt seen whipping out a gun in CCTV footage capturing the leadup to a daring hospital murder in Patna was arrested from Calcutta on Saturday night with three accomplices, police said on Sunday.

The suspect, Tauseef, purportedly led four other gunmen into the ICU of Paras Hospital and shot dead ailing gangster Chandan Mishra, who was in police custody, on Thursday.

Kolkata Police’s special task force (STF) detained him and four others, including a woman, from a guesthouse in Anandapur, on Calcutta’s southeast fringes, on Saturday evening for questioning.

While the woman was later released, a Patna police team that was in Calcutta arrested the four men on charges of conspiracy and murder.

Tauseef’s cousin Yousuf Khan alias Nishu — at whose home the hospital shooting was plotted, Patna police claimed — was among those arrested, sources said. The other two arrested men are the ailing Nishu’s male nurse Harsh Kumar and attendant Bhim Kumar.

Nishu has had two old bullets lodged inside his body and is currently bedridden. He was brought out of the guesthouse on a stretcher and taken to hospital.

Five other men who had been detained on Saturday morning from the Shukhobrishti housing complex in New Town were released after interrogation. No links were found between them and the Patna shooting, sources in the Bengal police said.

Officers said a gangster named Sheru — accused in multiple jewellery heists in Bengal and lodged in a Purulia jail — had asked Nishu to eliminate his rival Mishra.

Nishu allegedly engaged his cousin Tauseef for the job, for which a sum of ₹10 lakh was paid, police sources said.

After being brought to Alipore court in an ambulance on Sunday, Nishu told reporters he had no idea about the plot to assassinate Mishra.

“Mere bhai Tauseef ne nadani kar di (My brother Tauseef committed a childish act),” he said from inside the ambulance.

An officer with the Kolkata Police STF said: “After killing Mishra, Tauseef and his gang took shelter at Nishu’s home before they set off for Calcutta.”

He added: “The Patna police had been tracking Tauseef’s phone. Although he changed SIM cards a dozen times, he did not change his handset. His phone’s IMEI number gave away the details of all the SIM cards he had inserted in it.”

Tauseef and the others were captured on the basis of leads — including a car number —that the Patna police had provided to their Bengal and Calcutta counterparts.

The gang had entered Calcutta via the Vidyasagar Setu and gone to Shukhobrishti on Friday.

“We went to meet one of Tauseef’s friends, Ehsaan. But he was not there; so we returned,” Nishu told reporters.

“We tried unsuccessfully to get a room at a Park Street hotel. Then, on my girlfriend’s suggestion, we went to the guesthouse in Anandapur on Friday.”

After a daylong search on Saturday, a team from the Kolkata Police STF spotted their vehicle in Anandapur. While the four men were arrested, Nishu’s girlfriend was let go after questioning.

Sources said the gang had left their arms behind in Patna and travelled to Calcutta solely to hide.

Nishu claimed he was anyway coming to Calcutta to pick up his girlfriend and take her to Delhi where he planned to be treated for his injuries.

Police sources said Nishu had taken one of the two bullets in a police encounter and the other in a gunfight with a rival.

Nishu, who claimed to be a “developer”, said he had been shot “during a land dispute”.

The Alipore court on Sunday gave the Patna police two days’ transit remand of all the four arrested men.