Police are investigating medical drugs being stolen from an air ambulance helicopter at Taieri airfield

Medical equipment and supplies were also taken from the Queenstown rescue helicopter over the weekend.

It had just taken a critically ill patient to Dunedin Hospital, and was grounded at the base due to bad weather.

Detective Sergeant Grahame Gale says the theft is concerning on many levels.

He some of the drugs could be fatal if the wrong combination or dosage is consumed.

Police are appealing for information.