The motive behind the stabbing of actor Saif Ali Khan is still unclear and sustained interrogation of the accused is under way to untangle several intriguing questions, police said, rubbishing claims that the person caught on CCTV cameras on the day of the assault and the man in custody were not the same.

Accused Mohammad Shariful Islam Shahzad, 30, said to be a Bangladeshi national who entered India illegally and assumed the Hindu name Vijay Das, was arrested from Thane in the small hours of Sunday. Saif had been stabbed multiple times by a man who had sneaked into his 12th-floor apartment in upscale Bandra between 2am and 2.30am on January 16. The police have described the crime as a “failed robbery bid”.

“The custodial interrogation of the accused is continuing. So far, the precise motive behind the incident remains unclear,” said a police officer who is part of the team probing the incident.

Though the Bandra police, he said, have registered a case of attempted robbery, causing grievous hurt with an intention of robbery, trespass and other offences, there are doubts over the circumstances of the incident.

“There are some questions which remain unanswered,” said the officer, adding that investigators would soon take the accused to the place of occurrence and recreate the crime scene at Saif’s Bandra home.

Hours after his arrest on Sunday, deputy commissioner of police Dixit Gedam had said Shahzad was trying to rob Saif’s house without realising it belonged to a Bollywood actor. Later, the police produced him before a local court and informed the magistrate that they suspected an “international conspiracy” behind the incident.

According to the police complaint by Eliyamma Philip, nanny to the actor’s four-year-old son Jeh, the accused allegedly tried to hold the child and her hostage, demanded ₹1 crore and assaulted her. Confronted by Saif, he allegedly stabbed the actor multiple times before fleeing.

Speaking to The Telegraph over the phone from Mumbai, Gedam on Monday said Shahzad was the same person seen in the video footage, obtained from the staircase of Saif’s building, earlier released by the police.

Several social media users have flagged the “stark difference” in the facial features of the arrested accused and the person seen in the CCTV footage.

“The questions being raised over the difference between the facial features of the arrested person and the one in the footage are totally rubbish. The media has only two pieces of footage of the accused, which had been released earlier. We have several videos of him from different angles, including some in high resolution, which clearly establish the identity of the accused,” said Gedam, who is heading the probe.

After the initial interrogation of Shahzad, sources said, the police have learnt that the accused had taken the stairs to reach the 7th floor, entered the duct area, climbed a pipe to gain access to the 12th floor and entered Saif’s apartment through a bathroom window.

The preliminary probe suggests that Jeh’s nanny saw the intruder coming out of the bathroom. He held the nanny at knife-point and demanded ₹1 crore. Hearing the commotion, Saif rushed in and confronted the intruder, who got startled and stabbed him several times. The officer who spoke on the condition of anonymity said it was still not clear how the intruder escaped.

According to him, the accused slept at a bus stop near Patwardhan Garden in Bandra West till 7am on January 16 and later changed his clothes and boarded a train to Worli in central Mumbai.

The police have said they have seized a hammer, a screwdriver, a nylon rope and other materials from Shahzad’s bag.

A phone payment by Shahzad was a major lead that eventually helped the Mumbai police to track him down, sources said. He made a UPI transaction for a paratha and a bottle of water at a stall near Century Mill in Worli. The online transaction led the police to the accused’s mobile number, which was then traced to Thane. A team of 100 policemen arrested Shahzad from a bushy area near a labour camp.

PTI reported that Shahzad hid in the garden of the Bandra building for two hours after stabbing Saif. The accused initially tried to mislead investigators by claiming that he was a Calcutta resident, but his school-leaving certificate obtained from his Bangladesh-based brother “nailed his lie”, another police officer said.

Doctors at Mumbai’s Lilavati Hospital, where Saif is undergoing treatment, said the actor was recovering and might be discharged soon.