A five-month-old baby boy has been taken to hospital in a critical condition, prompting child protection detectives to launch an investigation.

Emergency services were called to the Ipswich suburb of Bundamba at 3.30pm on Tuesday, after the infant reportedly suffered a medical episode.

The baby boy was taken to Queensland Children's Hospital, where he remains.

Police have established a crime scene and investigations are ongoing.

Police would not comment on the infant's injuries.