Man questioned over boy's death released

A man who was questioned over the death of a toddler north of Brisbane has been released without charge.

Police were called to a house at Caboolture about 12.30am on Saturday, after ambulance officers found the body of the 21-month-old boy inside.

A 35-year-old man who spent Saturday being questioned by police was released overnight, a police spokesman said.

Preliminary investigations have confirmed the boy had sustained injuries and police are awaiting the results of a post-mortem examination.