The death of a baby boy who was found unresponsive at a Mackay home is being treated as suspicious by police.
Paramedics were called to the East Mackay family home about 2pm on June 2, where they discovered six-month-old Beau Frank Bradshaw.
Police believe he was alive and well at Illawong Beach, also known as Far Beach, just hours earlier.
He was taken to Mackay Base Hospital before being transferred to Townsville Hospital, where he died two days later.
There was no history of engagement between his family and the department of child safety before the baby's death, Detective Acting Inspector Mick Searle says.
Local detectives, intelligence officers, scientific and crime scene officers, and specialist police from the state crime command's child trauma unit are investigating his death.
"No bit of information is unimportant to us," Det Insp Searle said.
"We want to know whatever anyone knows out there to try and piece together exactly what's happened with this."
Anyone with any information is urged to contact police, specifically anyone who was in or captured photos or videos in the vicinity of Illawong Beach between 9.30am and 11am on June 2.