A Rotorua mother jailed this week for suffocating her baby while drunkenly sleeping was thought to have been "coping" by Child, Youth and Family before the tragedy.
The agency was unaware Ngaire Kura Tukiwaho had given birth to Tahi Elvis Edwards, who died at just 2 months old as she slept on him in the back of a parked car after a day of drinking in January last year.
Social Development Minister Paula Bennett has ordered an investigation into the circumstances surrounding the death.
Three years earlier, Tukiwaho, 30, lost a 1-month-old son, Hoani Benino, to cot death and was advised of safe sleeping practices.
"It appears there was a level of dysfunction in this household that we were not aware of," CYF head Bernadine MacKenzie said.