Amritpal Singh Sachdeva (57) - the man behind the death of 70 people and misery of hundreds - will continue to be a rich man, despite being behind bars.
Sachdeva built 40 rooms in the seven-storeyed structure and was earning almost Rs 1.5 lakh per month as rent.
However, every time the occupants of the building went to complain about waterlogging in the basement, Sachdeva turned them away, saying he had no money for repair work.
Although Sachdeva has 21 properties in his name across Delhi and Ghaziabad acquired through ill-gotten money, police will be looking into the money trail only in the present case.
Delhi Police are looking for documents pertaining to the illegal structure that Sachdeva built over a period of many years. "Our prime concern is to find the documents related to the building. This is a crucial piece of evidence," said IB Rani, additional deputy commissioner of police (east).
Sachdeva told the police that there were 40 rooms in the building and he used to charge R600 from each dweller.
Mohammad Dilshad, who was running a sweatshop from the building, said he had demolished the walls of four rooms taken on rent to turn it into one big hall and used to pay Rs 2,000 per month as rent.