Police were called by the London Ambulance Service at approximately 6.55am on Monday, 12 July to New Park Road, SW2. Officers attended and found the body of a 44-year-old man.
His next of kin have been informed and are being supported by specialist officers. We await formal identification.
A special post-mortem examination held at Greenwich Mortuary gave the provisional cause of death as multiple injuries.
Detectives from the Specialist Crime Command are leading the investigation.
A 48-year-old man [A] was arrested on suspicion of murder on Wednesday, 14 July. He remains in custody at a south London police station.
Anyone with any information is asked to contact police via 101 quoting reference Cad 1940/12Jul. To remain anonymous, call Crimestoppers on 0800 555 111.