The woman who was hospitalised after suffering a "serious gunshot wound" on Sunday at Mourea remains in a critical condition.

A police cordon was put in place around The Happy Angler Store & Takeaway on Sunday morning. Outside the building was a grey four-door ute with its doors open and a back window that appeared to be smashed.

The owner of Happy Angler Store & Takeaway declined to comment while a police investigation was ongoing.

Detective Senior Sergeant Ryan Yardley said police were alerted to the incident on State Highway 33, Mourea at about 1.55am.

"On arrival, a woman was located with a serious gunshot wound," Yardley said in a statement. "There have been no arrests at this time."

Yardley said there would be an increased police presence while inquiries were under way. As of 6pm on Sunday, those involved had not been located.

A St John spokesperson said they were notified at 1.59am and transported one patient with critical injuries to Rotorua Hospital.

Anyone with information is asked to contact police on 105 and quote event number P052026626.

Information can also be provided anonymously to Crime Stoppers on 0800 555 111.

Te Whatu Ora Lakes said the woman was transferred from Rotorua Hospital to Waikato Hospital this morning.

A Waikato DHB spokesman said Tuesday morning the woman remained in a critical condition.

Police have been approached for an update this morning.