The emergency services were called to a flat in Kingston Road near the library last night at around 9pm.
His death is being treated as unexpected and his family has been informed.
A number of other flats were evacuated at the time due to substances being found during a search inside the address.
A Met Police spokesperson said:
Police were called by the London Ambulance Service at 21:05hrs on Wednesday, the 14th of February to a flat on Kingston Road in New Malden following reports of a man found deceased.
The death is currently being treated as unexpected and is under investigation.
His next of kin has been informed.
Due to a number of substances being found inside the address, protective equipment was deployed for officer safety while a further search was carried out.
Several flats were evacuated as a safety precaution. Residents have since returned to their properties.
