Ms Brodie said an ambulance, a Fire Service crew and a second ambulance arrived at the scene within minutes, followed by police. The distraught mother had mentioned the boy had health issues in the past, Ms Brodie said.
"She did say he's been sick and that he does get asthma."
The boy's mother also had two other young children.
She had been living at the motor lodge while she waited for a Housing New Zealand house to become available.
"She's trying to make a better life for these kids."
Detective Sergeant Darren Pritchard said police and ambulance services were called to the motel on Karamu Rd, Mayfair, about 9am, where they found the 6-month-old boy unresponsive.
Mr Pritchard said attempts to revive the boy were unsuccessful.
He said at this stage it was unknown how the boy died.
The death is now under police investigation and "a number of people" will be spoken to, Mr Pritchard said.
The post-mortem examination results are expected today.
The case would be referred to the coroner.