Rotorua police are investigating the theft of vital emergency equipment from an ambulance overnight.

A defibrillating device, worth about $36,000, and two oxygen gas bottles were stolen from the ambulance while officers attended to a drunk teen at a party in Vaughan Rd about 3am, Rotorua police Senior Sergeant Dennis Murphy said.

The defibrillator was this morning found hidden not far from the property after a tip off to the local community constable.

Mr Murphy said the "callous theft" could have put lives at risk and was "a new low for thieves".

The intoxicated 17-year-old girl was also a serious problem, he said.

"The major concern with young people consuming large amounts of alcohol is that they are more likely to become a victim of crime, especially young females who are particularly vulnerable and unable to make good decisions about keeping themselves safe."

Mr Murphy said anyone with information about the theft should contact police.