Detectives from the Specialist Crime Command are investigating following the death of a child.
The investigation follows a call to officers at 06:06hrs, on Tuesday, 27 August, to a residential address in Putney, SW15.
LAS informed police they were responding to reports of a child in cardiac arrest.
The child, who was aged 15 months, was taken to a west London hospital and pronounced dead at 07:22hrs.
The family are aware.
A post-mortem examination took place on Friday, 29 August at Great Ormond Street Hospital.
Further tests are due to take place, however the death is being treated as suspicious.
A man and a woman, both aged 29 and who both resided at the address, were arrested on suspicion of murder.
They have both been bailed, the man to a date in early September and the woman to date in late September.