A woman who was found with critical injuries on Charlemont St in Hamilton on Saturday has since died.

Police were called to the scene shortly after 8pm on Saturday to find a 24-year-old woman with critical injuries.

The woman was transported to Waikato Hospital where she died overnight last night.

Waikato Police are continuing to make inquiries into the death and it is being treated as unexplained.

Police earlier stated that the woman was found without any major visible injuries, and her injuries were unexplained.

But a local resident believed she likely suffered a head injury after possibly being hit by a car.

As part of the ongoing inquiry police are appealing for anyone who saw a silver station wagon in and around the Charlemont and Ulster St areas between 7-8pm on Saturday.

A resident of Charlemont St earlier told the Herald he believed the woman had earlier been drinking with her partner and his family.

Ryan Mirfin, 24, said he and a friend were watching a movie when they heard a commotion outside. He looked out the window to see a group of people on the road.

"We kind of heard someone shouting about calling an ambulance and ran out there and my friend just took charge. She was really good in the situation. She's done first aid training."

A man who the injured woman had been drinking with was also there. After considering what to do - the man didn't want an ambulance called - they decided to drive the woman to hospital themselves.

Mirfin said he understood both the woman and the man were from out of town.

As for what happened, it was unclear, but they'd understood that the woman may have suffered a head injury as another person was moving their car. It didn't appear any malice was involved, he said.

She had either suffered the injury from the car itself or from landing on the road.

"She had few scrapes on her knees but seemed okay. To me, she just seemed to be showing all the signs of being drunk.

"From the sounds of things she may have walked into a car ... I don't think it was too malicious but I didn't see anything. By the time I saw her they had moved her onto the kerb."

Anyone with information is asked to call Hamilton Central Police Station on 07 858 6200, or Crimestoppers anonymously on 0800 555 111.