Detectives, in conjunction with the Health and Safety Executive (HSE), are investigating two unexplained deaths at a residential address on Bacon Lane in Edgware.
Police were called at 13:30hrs on Sunday, 8 April following reports of two males unresponsive.
Officers, the London Ambulance Service and London Fire Brigade attended. Two men, aged 35 and 42 years old, were found deceased at the address.
The deaths are being treated as unexplained; post-mortem examinations will be held in due course.
At this early stage, it is believed that there may have been a carbon monoxide leak at the address.
Five other people residing at the property - which is a multiple occupancy address - were taken to hospital as a precautionary measure. They have since been discharged.
A neighbouring property was also evacuated as a precaution but the residents have since been allowed to return.
The have been no arrests and enquiries continue.