Police are investigating the unexplained death of a two-year-old girl.

About 11am Saturday, police were flagged down by the occupants of a vehicle on Heaphy Terrace, Hamilton, who requested assistance with an unresponsive child.

The child was transported to hospital where she died Saturday evening, says a police spokesperson.

"At this stage the death is being treated as unexplained.

"A scene examination has been completed at the child's home address and a post-mortem examination will be conducted today.

"Police extends its sympathies to the girl's whanau at this difficult time.

"Police are speaking with a number of people in relation to the death."