The circumstances surrounding the death of a man in Neath are to be investigated by the Independent Police Complaints Commission (IPCC).
Police were called around 1900 GMT to help Jeremy Howard Gethin, 43, described as drunk and collapsed on a street corner on Saturday.
Paramedics checked a cut to his head but decided he did not need treatment.
He was dropped off outside his home by two officers but fell again after they left and died three days later.
Following the second fall he was taken from outside his home in the Clyne area by ambulance to Swansea's Morriston Hospital.
Mr Gethin was then transferred to the University Hospital Wales in Cardiff, where he underwent surgery the next day.
He died on Tuesday.
IPCC Commissioner for Wales Tom Davies said: "My sympathies go to Mr Gethin's family and friends for their tragic loss.
"We will carry out a focused investigation which will look at the decision to take Mr Gethin home.
"We will assess whether the decision-making was proportionate and in keeping with force policy and training."