The probe has found that when Bajaj acquired the building, it had two storeys. Additional floors were subsequently constructed, during which the alternative exit route at the rear was allegedly closed, police said.The Delhi Police investigation into the June 3 fire at a bed and breakfast (B&B) property in Malviya Nagar, in which 23 people, including foreign nationals, died, has found that an alternative exit at the rear of the building was blocked during construction, allegedly to create additional rooms and run the property as a full-fledged hotel.The police on Tuesday filed a nearly 1,500-page chargesheet against three accused – property owner Lavkesh Bajaj, manager-cum-accountant Jai Mishra and cook Kesar Negi.While Negi is out on bail, Bajaj and Mishra are in judicial custody. Bajaj is currently undergoing treatment at RML Hospital following complaints of severe abdominal pain.Police said Bajaj wanted to operate a hotel but did not have the requisite permissions or a fire clearance certificate. Instead, he allegedly obtained a licence under the Tourism department’s B&B scheme by showing the property as a residence owned by Mishra. Police alleged that Mishra submitted a false affidavit — he was not residing at the premises despite the B&B rules requiring the owner or operator to stay there.The probe has found that when Bajaj acquired the building, it had two storeys. Additional floors were subsequently constructed, during which the alternative exit route at the rear was allegedly closed, police said.Under the B&B scheme, permission had been granted for only six rooms at the property. However, the police found that 26 rooms were allegedly being operated there.The fire, which started on June 3, rapidly spread through the five-storey building. According to the probe, inflammable material at the premises and the absence of an alternative escape route contributed to the rapid spread of the fire. Once the building filled with smoke, occupants had limited options to escape, police said.Story continues below this adThe chargesheet names more than 130 witnesses, including public witnesses, and contains judicial and medical records along with other documents collected during the investigation.The final report of the Forensic Science Laboratory, however, is still awaited. Police may file a supplementary chargesheet after receiving it.The three accused have been chargesheeted under sections 105 (culpable homicide not amounting to murder), 326(g) (mischief by injury, inundation, fire or explosive substance), 324(5) (mischief), 125(a) and 125(b) (acts endangering human life or personal safety of others and causing grievous hurt by such acts) and 287 (negligent conduct with respect to fire or combustible matter) of the BNS, police said.According to the investigation, the fire started in the kitchen after Negi allegedly left an oil fryer switched on while preparing tea for himself. The oil reportedly reached its auto-ignition temperature and caught fire, setting the ceiling and nearby combustible material ablaze.Story continues below this adPolice alleged that Negi initially attempted to douse the flames but fled when they grew beyond his control without alerting the guests, neighbours or emergency services.