A 13-year-old is in Waikato Hospital after sustaining serious injuries when he fell from his mountain bike in the Whakarewarewa forest.

The Whangarei teenager was biking in the forest on the outskirts of Rotorua when he 'took a tumble from his bike” about 1pm yesterday.

File photo.

St John paramedics were called to the scene but the teen had to be winched using the First Sovereign Trust Rescue Winch on the BayTrust Rescue Helicopter so he could be flown to hospital.

Pilot and base manager Barry Vincent says he was stabilised by the chopper crew after being winched out and then due to the serious nature of his injuries he was airlifted directly to Waikato hospital in serious condition.

'This is the second time in 24 hours the winch has been used to assist people with serious injuries.”