Police believe crucial evidence was disposed of in the case of Lower Hutt toddler Ruthless-Empire

He died on October 22, with severe intentional injuries to his head.

Police this morning asked for sightings of a grey green Nissan Sentra, between October 22 and 24.

Herald Reporter Melissa Nightingale says Police say three adults went in the car with the toddler to the hospital.

She says Police say somebody returned in that car three times to the house - and removed what Police have called critical evidence, in an attempt to clean up the scene.