A father and his son have died after being struck by a ute south of Brisbane.

The two pedestrians were hit by a ute on Green Rd at Regents Park in the city of Logan just after 11am on Sunday.

Queensland Ambulance Service said it had treated two people at the scene — a 33-year-old man and a four-year-old boy — for life-threatening injuries but did not transport anyone to hospital.

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Queensland Police were earlier unable to confirm if the man and child had lost their lives in the crash but if paramedics do not take patients with life-threatening injuries to hospital, it is understood they have tragically died at the scene.

Footage from the scene showed a broken children’s bike lying on the footpath.

Police confirmed the man and boy, both from nearby Crestmead, are known to each other.

The driver of the white LDV dual cab ute, a 41-year-old from Regents Park, was not injured.

He was taken into custody at the scene and is assisting officers. 7NEWS understands he failed a roadside breath test.