The Bangladeshi national arrested for the January 16 knife attack on Saif Ali Khan entered the country illegally seven months ago and used a West Bengal resident's Aadhaar card to procure a SIM card before moving to Mumbai, the police said on Tuesday.
The police arrested the accused, Shariful Islam Shehzad Mohammad Rohilla Amin Fakir (30), on Sunday from neighbouring Thane city for the stabbing incident at the Bollywood star's residence in Bandra.
According to the police, Fakir, who changed his name to Vijay Das, crossed the Dawki River to enter India illegally seven months ago.
An official said the accused stayed for a few weeks in West Bengal and used the Aadhaar card of a local man to procure a SIM card before moving to Mumbai in search of a job.
He said the preliminary probe revealed that the SIM card used by the accused was registered in the name of one Khukumoni Jahangir Sekha of West Bengal.
The official said Fakir also tried to get an Aadhaar card for himself but failed.
He said in Mumbai, the accused chose to work at places where he didn't need to furnish documents, and labour contractor Amit Pandey helped him get housekeeping work in pubs and hotels in Worli and Thane.
On examining Fakir's cellphone, the police found he had made several calls to Bangladesh and used mobile applications to make calls to his family in the neighbouring country.
Khan (54) was stabbed repeatedly by the intruder inside his 12-floor apartment in the building on January 16, necessitating surgery. The metropolitan magistrate's court in Bandra has remanded the accused in five-day police custody.