The Lagos State Emergency Agency had earlier confirmed that two persons died in the accident.
The third victim had been rushed to the Lagos State Teaching Hospital for treatment, LASEMA chief, Dr Femi Osanyintolu said.
However, the victim failed to recover from injuries sustained and died later on Friday, spokesperson for the AIB, Mr Tunji Oketunmbi, confirmed to Channels Television.
All three victims were on board the helicopter before it crashed.
No one on the ground was hurt, LASEMA officials said.
The helicopter, a Bell 206, with registration number 5N BQW belonged to Quorum Aviation.
It was travelling in from Port Harcourt, the Rivers state capital with two crew members and a passenger before it crashed into a residential building in the Opebi area of Lagos on Friday.
Earlier, the AIB said it had recovered the helicopter’s black box, commencing investigations into the cause of the crash.
