Detective Inspector Mike Foster says the critical injuries sustained by a 4-year-old boy are some of the most severe injuries he has seen on a child in 30 years of policing.

Police continue to make inquiries into the incident that lead to the boy's injuries at Ramsey Crescent, Flaxmere on January 29, and are seeking any further information which may help.

The child remains in a serious condition in a ward in Starship Hospital, and is likely to be severely disabled and brain damaged if he survives.

Police have been speaking to a number of people in relation to the boy's injuries, but would ask anyone else who may be able to help, to come forward.

"We would urge people to do the right thing by this child and help us work out exactly what's happened," Detective Inspector Foster says.

"Please let us know anything that may help, no matter how small."